277 files changed, 4751 insertions, 4434 deletions

diff --git a/synapse/__init__.py b/synapse/__init__.py
index ee3313a41c..bcc2f8c049 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -36,7 +36,7 @@ try:
 except ImportError:
     pass
 
-__version__ = "1.4.1"
+__version__ = "1.5.0rc1"
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when
diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index cd347fbe1b..53f3bb0fa8 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -25,7 +25,13 @@ from twisted.internet import defer
 import synapse.logging.opentracing as opentracing
 import synapse.types
 from synapse import event_auth
-from synapse.api.constants import EventTypes, JoinRules, Membership, UserTypes
+from synapse.api.constants import (
+    EventTypes,
+    JoinRules,
+    LimitBlockingTypes,
+    Membership,
+    UserTypes,
+)
 from synapse.api.errors import (
     AuthError,
     Codes,
@@ -726,7 +732,7 @@ class Auth(object):
                 self.hs.config.hs_disabled_message,
                 errcode=Codes.RESOURCE_LIMIT_EXCEEDED,
                 admin_contact=self.hs.config.admin_contact,
-                limit_type=self.hs.config.hs_disabled_limit_type,
+                limit_type=LimitBlockingTypes.HS_DISABLED,
             )
         if self.hs.config.limit_usage_by_mau is True:
             assert not (user_id and threepid)
@@ -759,5 +765,5 @@ class Auth(object):
                     "Monthly Active User Limit Exceeded",
                     admin_contact=self.hs.config.admin_contact,
                     errcode=Codes.RESOURCE_LIMIT_EXCEEDED,
-                    limit_type="monthly_active_user",
+                    limit_type=LimitBlockingTypes.MONTHLY_ACTIVE_USER,
                 )
diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 60e99e4663..312196675e 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -131,3 +131,10 @@ class RelationTypes(object):
     ANNOTATION = "m.annotation"
     REPLACE = "m.replace"
     REFERENCE = "m.reference"
+
+
+class LimitBlockingTypes(object):
+    """Reasons that a server may be blocked"""
+
+    MONTHLY_ACTIVE_USER = "monthly_active_user"
+    HS_DISABLED = "hs_disabled"
diff --git a/synapse/app/event_creator.py b/synapse/app/event_creator.py
index c67fe69a50..f20d810ece 100644
--- a/synapse/app/event_creator.py
+++ b/synapse/app/event_creator.py
@@ -56,8 +56,8 @@ from synapse.rest.client.v1.room import (
     RoomStateEventRestServlet,
 )
 from synapse.server import HomeServer
+from synapse.storage.data_stores.main.user_directory import UserDirectoryStore
 from synapse.storage.engines import create_engine
-from synapse.storage.user_directory import UserDirectoryStore
 from synapse.util.httpresourcetree import create_resource_tree
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
diff --git a/synapse/app/media_repository.py b/synapse/app/media_repository.py
index 2ac783ffa3..6bc7202f33 100644
--- a/synapse/app/media_repository.py
+++ b/synapse/app/media_repository.py
@@ -39,8 +39,8 @@ from synapse.replication.tcp.client import ReplicationClientHandler
 from synapse.rest.admin import register_servlets_for_media_repo
 from synapse.rest.media.v0.content_repository import ContentRepoResource
 from synapse.server import HomeServer
+from synapse.storage.data_stores.main.media_repository import MediaRepositoryStore
 from synapse.storage.engines import create_engine
-from synapse.storage.media_repository import MediaRepositoryStore
 from synapse.util.httpresourcetree import create_resource_tree
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
diff --git a/synapse/app/synchrotron.py b/synapse/app/synchrotron.py
index 473026fce5..6a7e2fa707 100644
--- a/synapse/app/synchrotron.py
+++ b/synapse/app/synchrotron.py
@@ -54,8 +54,8 @@ from synapse.rest.client.v1.initial_sync import InitialSyncRestServlet
 from synapse.rest.client.v1.room import RoomInitialSyncRestServlet
 from synapse.rest.client.v2_alpha import sync
 from synapse.server import HomeServer
+from synapse.storage.data_stores.main.presence import UserPresenceState
 from synapse.storage.engines import create_engine
-from synapse.storage.presence import UserPresenceState
 from synapse.util.httpresourcetree import create_resource_tree
 from synapse.util.manhole import manhole
 from synapse.util.stringutils import random_string
diff --git a/synapse/app/user_dir.py b/synapse/app/user_dir.py
index e01afb39f2..a5d6dc7915 100644
--- a/synapse/app/user_dir.py
+++ b/synapse/app/user_dir.py
@@ -42,8 +42,8 @@ from synapse.replication.tcp.streams.events import (
 )
 from synapse.rest.client.v2_alpha import user_directory
 from synapse.server import HomeServer
+from synapse.storage.data_stores.main.user_directory import UserDirectoryStore
 from synapse.storage.engines import create_engine
-from synapse.storage.user_directory import UserDirectoryStore
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 from synapse.util.httpresourcetree import create_resource_tree
 from synapse.util.manhole import manhole
diff --git a/synapse/config/appservice.py b/synapse/config/appservice.py
index 9b4682222d..e77d3387ff 100644
--- a/synapse/config/appservice.py
+++ b/synapse/config/appservice.py
@@ -48,7 +48,7 @@ class AppServiceConfig(Config):
         # Uncomment to enable tracking of application service IP addresses. Implicitly
         # enables MAU tracking for application service users.
         #
-        #track_appservice_user_ips: True
+        #track_appservice_user_ips: true
         """
 
 
diff --git a/synapse/config/consent_config.py b/synapse/config/consent_config.py
index 62c4c44d60..aec9c4bbce 100644
--- a/synapse/config/consent_config.py
+++ b/synapse/config/consent_config.py
@@ -62,11 +62,11 @@ DEFAULT_CONFIG = """\
 #    body: >-
 #      To continue using this homeserver you must review and agree to the
 #      terms and conditions at %(consent_uri)s
-#  send_server_notice_to_guests: True
+#  send_server_notice_to_guests: true
 #  block_events_error: >-
 #    To continue using this homeserver you must review and agree to the
 #    terms and conditions at %(consent_uri)s
-#  require_at_registration: False
+#  require_at_registration: false
 #  policy_name: Privacy Policy
 #
 """
diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py
index 658897a77e..39e7a1dddb 100644
--- a/synapse/config/emailconfig.py
+++ b/synapse/config/emailconfig.py
@@ -304,13 +304,13 @@ class EmailConfig(Config):
         #   smtp_port: 25 # SSL: 465, STARTTLS: 587
         #   smtp_user: "exampleusername"
         #   smtp_pass: "examplepassword"
-        #   require_transport_security: False
+        #   require_transport_security: false
         #   notif_from: "Your Friendly %(app)s Home Server <noreply@example.com>"
         #   app_name: Matrix
         #
         #   # Enable email notifications by default
         #   #
-        #   notif_for_new_users: True
+        #   notif_for_new_users: true
         #
         #   # Defining a custom URL for Riot is only needed if email notifications
         #   # should contain links to a self-hosted installation of Riot; when set
diff --git a/synapse/config/metrics.py b/synapse/config/metrics.py
index 282a43bddb..22538153e1 100644
--- a/synapse/config/metrics.py
+++ b/synapse/config/metrics.py
@@ -70,7 +70,7 @@ class MetricsConfig(Config):
 
         # Enable collection and rendering of performance metrics
         #
-        #enable_metrics: False
+        #enable_metrics: false
 
         # Enable sentry integration
         # NOTE: While attempts are made to ensure that the logs don't contain
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index b3e3e6dda2..ab41623b2b 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -180,7 +180,7 @@ class RegistrationConfig(Config):
         # where d is equal to 10%% of the validity period.
         #
         #account_validity:
-        #  enabled: True
+        #  enabled: true
         #  period: 6w
         #  renew_at: 1w
         #  renew_email_subject: "Renew your %%(app)s account"
diff --git a/synapse/config/saml2_config.py b/synapse/config/saml2_config.py
index c407e13680..c5ea2d43a1 100644
--- a/synapse/config/saml2_config.py
+++ b/synapse/config/saml2_config.py
@@ -176,7 +176,7 @@ class SAML2Config(Config):
           #      - url: https://our_idp/metadata.xml
           #
           #    # By default, the user has to go to our login page first. If you'd like
-          #    # to allow IdP-initiated login, set 'allow_unsolicited: True' in a
+          #    # to allow IdP-initiated login, set 'allow_unsolicited: true' in a
           #    # 'service.sp' section:
           #    #
           #    #service:
diff --git a/synapse/config/server.py b/synapse/config/server.py
index afc4d6a4ab..d556df308d 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -171,6 +171,7 @@ class ServerConfig(Config):
         )
 
         self.mau_trial_days = config.get("mau_trial_days", 0)
+        self.mau_limit_alerting = config.get("mau_limit_alerting", True)
 
         # How long to keep redacted events in the database in unredacted form
         # before redacting them.
@@ -192,7 +193,6 @@ class ServerConfig(Config):
         # Options to disable HS
         self.hs_disabled = config.get("hs_disabled", False)
         self.hs_disabled_message = config.get("hs_disabled_message", "")
-        self.hs_disabled_limit_type = config.get("hs_disabled_limit_type", "")
 
         # Admin uri to direct users at should their instance become blocked
         # due to resource constraints
@@ -532,7 +532,7 @@ class ServerConfig(Config):
         # Whether room invites to users on this server should be blocked
         # (except those sent by local server admins). The default is False.
         #
-        #block_non_admin_invites: True
+        #block_non_admin_invites: true
 
         # Room searching
         #
@@ -673,9 +673,8 @@ class ServerConfig(Config):
 
         # Global blocking
         #
-        #hs_disabled: False
+        #hs_disabled: false
         #hs_disabled_message: 'Human readable reason for why the HS is blocked'
-        #hs_disabled_limit_type: 'error code(str), to help clients decode reason'
 
         # Monthly Active User Blocking
         #
@@ -695,15 +694,22 @@ class ServerConfig(Config):
         # sign up in a short space of time never to return after their initial
         # session.
         #
-        #limit_usage_by_mau: False
+        # 'mau_limit_alerting' is a means of limiting client side alerting
+        # should the mau limit be reached. This is useful for small instances
+        # where the admin has 5 mau seats (say) for 5 specific people and no
+        # interest increasing the mau limit further. Defaults to True, which
+        # means that alerting is enabled
+        #
+        #limit_usage_by_mau: false
         #max_mau_value: 50
         #mau_trial_days: 2
+        #mau_limit_alerting: false
 
         # If enabled, the metrics for the number of monthly active users will
         # be populated, however no one will be limited. If limit_usage_by_mau
         # is true, this is implied to be true.
         #
-        #mau_stats_only: False
+        #mau_stats_only: false
 
         # Sometimes the server admin will want to ensure certain accounts are
         # never blocked by mau checking. These accounts are specified here.
@@ -728,7 +734,7 @@ class ServerConfig(Config):
         #
         # Uncomment the below lines to enable:
         #limit_remote_rooms:
-        #  enabled: True
+        #  enabled: true
         #  complexity: 1.0
         #  complexity_error: "This room is too complex."
 
diff --git a/synapse/config/tls.py b/synapse/config/tls.py
index f06341eb67..2e9e478a2a 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -289,6 +289,9 @@ class TlsConfig(Config):
             "http://localhost:8009/.well-known/acme-challenge"
         )
 
+        # flake8 doesn't recognise that variables are used in the below string
+        _ = tls_enabled, proxypassline, acme_enabled, default_acme_account_file
+
         return (
             """\
         ## TLS ##
@@ -451,7 +454,11 @@ class TlsConfig(Config):
         #tls_fingerprints: [{"sha256": "<base64_encoded_sha256_fingerprint>"}]
 
         """
-            % locals()
+            # Lowercase the string representation of boolean values
+            % {
+                x[0]: str(x[1]).lower() if isinstance(x[1], bool) else x[1]
+                for x in locals().items()
+            }
         )
 
     def read_tls_certificate(self):
diff --git a/synapse/config/voip.py b/synapse/config/voip.py
index a68a3068aa..b313bff140 100644
--- a/synapse/config/voip.py
+++ b/synapse/config/voip.py
@@ -56,5 +56,5 @@ class VoipConfig(Config):
         # connect to arbitrary endpoints without having first signed up for a
         # valid account (e.g. by passing a CAPTCHA).
         #
-        #turn_allow_guests: True
+        #turn_allow_guests: true
         """
diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index 4e91df60e6..e7b722547b 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -493,8 +493,7 @@ def _check_power_levels(event, auth_events):
         new_level_too_big = new_level is not None and new_level > user_level
         if old_level_too_big or new_level_too_big:
             raise AuthError(
-                403,
-                "You don't have permission to add ops level greater " "than your own",
+                403, "You don't have permission to add ops level greater than your own"
             )
 
 
diff --git a/synapse/federation/sender/per_destination_queue.py b/synapse/federation/sender/per_destination_queue.py
index 0486af2dbf..d5d4a60c88 100644
--- a/synapse/federation/sender/per_destination_queue.py
+++ b/synapse/federation/sender/per_destination_queue.py
@@ -30,7 +30,7 @@ from synapse.federation.units import Edu
 from synapse.handlers.presence import format_user_presence_state
 from synapse.metrics import sent_transactions_counter
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.storage import UserPresenceState
+from synapse.storage.presence import UserPresenceState
 from synapse.util.retryutils import NotRetryingDestination, get_retry_limiter
 
 # This is defined in the Matrix spec and enforced by the receiver.
diff --git a/synapse/replication/slave/storage/account_data.py b/synapse/replication/slave/storage/account_data.py
index 3c44d1d48d..bc2f6a12ae 100644
--- a/synapse/replication/slave/storage/account_data.py
+++ b/synapse/replication/slave/storage/account_data.py
@@ -16,8 +16,8 @@
 
 from synapse.replication.slave.storage._base import BaseSlavedStore
 from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
-from synapse.storage.account_data import AccountDataWorkerStore
-from synapse.storage.tags import TagsWorkerStore
+from synapse.storage.data_stores.main.account_data import AccountDataWorkerStore
+from synapse.storage.data_stores.main.tags import TagsWorkerStore
 
 
 class SlavedAccountDataStore(TagsWorkerStore, AccountDataWorkerStore, BaseSlavedStore):
diff --git a/synapse/replication/slave/storage/appservice.py b/synapse/replication/slave/storage/appservice.py
index cda12ea70d..a67fbeffb7 100644
--- a/synapse/replication/slave/storage/appservice.py
+++ b/synapse/replication/slave/storage/appservice.py
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.appservice import (
+from synapse.storage.data_stores.main.appservice import (
     ApplicationServiceTransactionWorkerStore,
     ApplicationServiceWorkerStore,
 )
diff --git a/synapse/replication/slave/storage/client_ips.py b/synapse/replication/slave/storage/client_ips.py
index 14ced32333..b4f58cea19 100644
--- a/synapse/replication/slave/storage/client_ips.py
+++ b/synapse/replication/slave/storage/client_ips.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.client_ips import LAST_SEEN_GRANULARITY
+from synapse.storage.data_stores.main.client_ips import LAST_SEEN_GRANULARITY
 from synapse.util.caches import CACHE_SIZE_FACTOR
 from synapse.util.caches.descriptors import Cache
 
diff --git a/synapse/replication/slave/storage/deviceinbox.py b/synapse/replication/slave/storage/deviceinbox.py
index 284fd30d89..9fb6c5c6ff 100644
--- a/synapse/replication/slave/storage/deviceinbox.py
+++ b/synapse/replication/slave/storage/deviceinbox.py
@@ -15,7 +15,7 @@
 
 from synapse.replication.slave.storage._base import BaseSlavedStore
 from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
-from synapse.storage.deviceinbox import DeviceInboxWorkerStore
+from synapse.storage.data_stores.main.deviceinbox import DeviceInboxWorkerStore
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
diff --git a/synapse/replication/slave/storage/devices.py b/synapse/replication/slave/storage/devices.py
index f045e1b937..61557665a7 100644
--- a/synapse/replication/slave/storage/devices.py
+++ b/synapse/replication/slave/storage/devices.py
@@ -15,8 +15,8 @@
 
 from synapse.replication.slave.storage._base import BaseSlavedStore
 from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
-from synapse.storage.devices import DeviceWorkerStore
-from synapse.storage.end_to_end_keys import EndToEndKeyWorkerStore
+from synapse.storage.data_stores.main.devices import DeviceWorkerStore
+from synapse.storage.data_stores.main.end_to_end_keys import EndToEndKeyWorkerStore
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
 
diff --git a/synapse/replication/slave/storage/directory.py b/synapse/replication/slave/storage/directory.py
index 1d1d48709a..8b9717c46f 100644
--- a/synapse/replication/slave/storage/directory.py
+++ b/synapse/replication/slave/storage/directory.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.directory import DirectoryWorkerStore
+from synapse.storage.data_stores.main.directory import DirectoryWorkerStore
 
 from ._base import BaseSlavedStore
 
diff --git a/synapse/replication/slave/storage/events.py b/synapse/replication/slave/storage/events.py
index ab5937e638..d0a0eaf75b 100644
--- a/synapse/replication/slave/storage/events.py
+++ b/synapse/replication/slave/storage/events.py
@@ -20,15 +20,17 @@ from synapse.replication.tcp.streams.events import (
     EventsStreamCurrentStateRow,
     EventsStreamEventRow,
 )
-from synapse.storage.event_federation import EventFederationWorkerStore
-from synapse.storage.event_push_actions import EventPushActionsWorkerStore
-from synapse.storage.events_worker import EventsWorkerStore
-from synapse.storage.relations import RelationsWorkerStore
-from synapse.storage.roommember import RoomMemberWorkerStore
-from synapse.storage.signatures import SignatureWorkerStore
-from synapse.storage.state import StateGroupWorkerStore
-from synapse.storage.stream import StreamWorkerStore
-from synapse.storage.user_erasure_store import UserErasureWorkerStore
+from synapse.storage.data_stores.main.event_federation import EventFederationWorkerStore
+from synapse.storage.data_stores.main.event_push_actions import (
+    EventPushActionsWorkerStore,
+)
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
+from synapse.storage.data_stores.main.relations import RelationsWorkerStore
+from synapse.storage.data_stores.main.roommember import RoomMemberWorkerStore
+from synapse.storage.data_stores.main.signatures import SignatureWorkerStore
+from synapse.storage.data_stores.main.state import StateGroupWorkerStore
+from synapse.storage.data_stores.main.stream import StreamWorkerStore
+from synapse.storage.data_stores.main.user_erasure_store import UserErasureWorkerStore
 
 from ._base import BaseSlavedStore
 from ._slaved_id_tracker import SlavedIdTracker
diff --git a/synapse/replication/slave/storage/filtering.py b/synapse/replication/slave/storage/filtering.py
index 456a14cd5c..5c84ebd125 100644
--- a/synapse/replication/slave/storage/filtering.py
+++ b/synapse/replication/slave/storage/filtering.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.filtering import FilteringStore
+from synapse.storage.data_stores.main.filtering import FilteringStore
 
 from ._base import BaseSlavedStore
 
diff --git a/synapse/replication/slave/storage/keys.py b/synapse/replication/slave/storage/keys.py
index cc6f7f009f..3def367ae9 100644
--- a/synapse/replication/slave/storage/keys.py
+++ b/synapse/replication/slave/storage/keys.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage import KeyStore
+from synapse.storage.data_stores.main.keys import KeyStore
 
 # KeyStore isn't really safe to use from a worker, but for now we do so and hope that
 # the races it creates aren't too bad.
diff --git a/synapse/replication/slave/storage/presence.py b/synapse/replication/slave/storage/presence.py
index 82d808af4c..747ced0c84 100644
--- a/synapse/replication/slave/storage/presence.py
+++ b/synapse/replication/slave/storage/presence.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 
 from synapse.storage import DataStore
-from synapse.storage.presence import PresenceStore
+from synapse.storage.data_stores.main.presence import PresenceStore
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
 from ._base import BaseSlavedStore, __func__
diff --git a/synapse/replication/slave/storage/profile.py b/synapse/replication/slave/storage/profile.py
index 46c28d4171..28c508aad3 100644
--- a/synapse/replication/slave/storage/profile.py
+++ b/synapse/replication/slave/storage/profile.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 
 from synapse.replication.slave.storage._base import BaseSlavedStore
-from synapse.storage.profile import ProfileWorkerStore
+from synapse.storage.data_stores.main.profile import ProfileWorkerStore
 
 
 class SlavedProfileStore(ProfileWorkerStore, BaseSlavedStore):
diff --git a/synapse/replication/slave/storage/push_rule.py b/synapse/replication/slave/storage/push_rule.py
index af7012702e..3655f05e54 100644
--- a/synapse/replication/slave/storage/push_rule.py
+++ b/synapse/replication/slave/storage/push_rule.py
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.push_rule import PushRulesWorkerStore
+from synapse.storage.data_stores.main.push_rule import PushRulesWorkerStore
 
 from ._slaved_id_tracker import SlavedIdTracker
 from .events import SlavedEventStore
diff --git a/synapse/replication/slave/storage/pushers.py b/synapse/replication/slave/storage/pushers.py
index 8eeb267d61..b4331d0799 100644
--- a/synapse/replication/slave/storage/pushers.py
+++ b/synapse/replication/slave/storage/pushers.py
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.pusher import PusherWorkerStore
+from synapse.storage.data_stores.main.pusher import PusherWorkerStore
 
 from ._base import BaseSlavedStore
 from ._slaved_id_tracker import SlavedIdTracker
diff --git a/synapse/replication/slave/storage/receipts.py b/synapse/replication/slave/storage/receipts.py
index 91afa5a72b..43d823c601 100644
--- a/synapse/replication/slave/storage/receipts.py
+++ b/synapse/replication/slave/storage/receipts.py
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.receipts import ReceiptsWorkerStore
+from synapse.storage.data_stores.main.receipts import ReceiptsWorkerStore
 
 from ._base import BaseSlavedStore
 from ._slaved_id_tracker import SlavedIdTracker
diff --git a/synapse/replication/slave/storage/registration.py b/synapse/replication/slave/storage/registration.py
index 408d91df1c..4b8553e250 100644
--- a/synapse/replication/slave/storage/registration.py
+++ b/synapse/replication/slave/storage/registration.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.registration import RegistrationWorkerStore
+from synapse.storage.data_stores.main.registration import RegistrationWorkerStore
 
 from ._base import BaseSlavedStore
 
diff --git a/synapse/replication/slave/storage/room.py b/synapse/replication/slave/storage/room.py
index f68b3378e3..d9ad386b28 100644
--- a/synapse/replication/slave/storage/room.py
+++ b/synapse/replication/slave/storage/room.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.room import RoomWorkerStore
+from synapse.storage.data_stores.main.room import RoomWorkerStore
 
 from ._base import BaseSlavedStore
 from ._slaved_id_tracker import SlavedIdTracker
diff --git a/synapse/replication/slave/storage/transactions.py b/synapse/replication/slave/storage/transactions.py
index 3527beb3c9..ac88e6b8c3 100644
--- a/synapse/replication/slave/storage/transactions.py
+++ b/synapse/replication/slave/storage/transactions.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.storage.transactions import TransactionStore
+from synapse.storage.data_stores.main.transactions import TransactionStore
 
 from ._base import BaseSlavedStore
 
diff --git a/synapse/server_notices/resource_limits_server_notices.py b/synapse/server_notices/resource_limits_server_notices.py
index 81c4aff496..c0e7f475c9 100644
--- a/synapse/server_notices/resource_limits_server_notices.py
+++ b/synapse/server_notices/resource_limits_server_notices.py
@@ -20,6 +20,7 @@ from twisted.internet import defer
 
 from synapse.api.constants import (
     EventTypes,
+    LimitBlockingTypes,
     ServerNoticeLimitReached,
     ServerNoticeMsgType,
 )
@@ -70,7 +71,7 @@ class ResourceLimitsServerNotices(object):
             return
 
         if not self._server_notices_manager.is_enabled():
-            # Don't try and send server notices unles they've been enabled
+            # Don't try and send server notices unless they've been enabled
             return
 
         timestamp = yield self._store.user_last_seen_monthly_active(user_id)
@@ -79,8 +80,6 @@ class ResourceLimitsServerNotices(object):
             # In practice, not sure we can ever get here
             return
 
-        # Determine current state of room
-
         room_id = yield self._server_notices_manager.get_notice_room_for_user(user_id)
 
         if not room_id:
@@ -88,51 +87,86 @@ class ResourceLimitsServerNotices(object):
             return
 
         yield self._check_and_set_tags(user_id, room_id)
+
+        # Determine current state of room
         currently_blocked, ref_events = yield self._is_room_currently_blocked(room_id)
 
+        limit_msg = None
+        limit_type = None
         try:
-            # Normally should always pass in user_id if you have it, but in
-            # this case are checking what would happen to other users if they
-            # were to arrive.
-            try:
-                yield self._auth.check_auth_blocking()
-                is_auth_blocking = False
-            except ResourceLimitError as e:
-                is_auth_blocking = True
-                event_content = e.msg
-                event_limit_type = e.limit_type
-
-            if currently_blocked and not is_auth_blocking:
-                # Room is notifying of a block, when it ought not to be.
-                # Remove block notification
-                content = {"pinned": ref_events}
-                yield self._server_notices_manager.send_notice(
-                    user_id, content, EventTypes.Pinned, ""
-                )
+            # Normally should always pass in user_id to check_auth_blocking
+            # if you have it, but in this case are checking what would happen
+            # to other users if they were to arrive.
+            yield self._auth.check_auth_blocking()
+        except ResourceLimitError as e:
+            limit_msg = e.msg
+            limit_type = e.limit_type
 
-            elif not currently_blocked and is_auth_blocking:
+        try:
+            if (
+                limit_type == LimitBlockingTypes.MONTHLY_ACTIVE_USER
+                and not self._config.mau_limit_alerting
+            ):
+                # We have hit the MAU limit, but MAU alerting is disabled:
+                # reset room if necessary and return
+                if currently_blocked:
+                    self._remove_limit_block_notification(user_id, ref_events)
+                return
+
+            if currently_blocked and not limit_msg:
+                # Room is notifying of a block, when it ought not to be.
+                yield self._remove_limit_block_notification(user_id, ref_events)
+            elif not currently_blocked and limit_msg:
                 # Room is not notifying of a block, when it ought to be.
-                # Add block notification
-                content = {
-                    "body": event_content,
-                    "msgtype": ServerNoticeMsgType,
-                    "server_notice_type": ServerNoticeLimitReached,
-                    "admin_contact": self._config.admin_contact,
-                    "limit_type": event_limit_type,
-                }
-                event = yield self._server_notices_manager.send_notice(
-                    user_id, content, EventTypes.Message
+                yield self._apply_limit_block_notification(
+                    user_id, limit_msg, limit_type
                 )
-
-                content = {"pinned": [event.event_id]}
-                yield self._server_notices_manager.send_notice(
-                    user_id, content, EventTypes.Pinned, ""
-                )
-
         except SynapseError as e:
             logger.error("Error sending resource limits server notice: %s", e)
 
     @defer.inlineCallbacks
+    def _remove_limit_block_notification(self, user_id, ref_events):
+        """Utility method to remove limit block notifications from the server
+        notices room.
+
+        Args:
+            user_id (str): user to notify
+            ref_events (list[str]): The event_ids of pinned events that are unrelated to
+            limit blocking and need to be preserved.
+        """
+        content = {"pinned": ref_events}
+        yield self._server_notices_manager.send_notice(
+            user_id, content, EventTypes.Pinned, ""
+        )
+
+    @defer.inlineCallbacks
+    def _apply_limit_block_notification(self, user_id, event_body, event_limit_type):
+        """Utility method to apply limit block notifications in the server
+        notices room.
+
+        Args:
+            user_id (str): user to notify
+            event_body(str): The human readable text that describes the block.
+            event_limit_type(str): Specifies the type of block e.g. monthly active user
+            limit has been exceeded.
+        """
+        content = {
+            "body": event_body,
+            "msgtype": ServerNoticeMsgType,
+            "server_notice_type": ServerNoticeLimitReached,
+            "admin_contact": self._config.admin_contact,
+            "limit_type": event_limit_type,
+        }
+        event = yield self._server_notices_manager.send_notice(
+            user_id, content, EventTypes.Message
+        )
+
+        content = {"pinned": [event.event_id]}
+        yield self._server_notices_manager.send_notice(
+            user_id, content, EventTypes.Pinned, ""
+        )
+
+    @defer.inlineCallbacks
     def _check_and_set_tags(self, user_id, room_id):
         """
         Since server notices rooms were originally not with tags,
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index e9a9c2cd8d..a249ecd219 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -14,515 +14,20 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import calendar
-import logging
-import time
-
-from twisted.internet import defer
-
-from synapse.api.constants import PresenceState
-from synapse.storage.devices import DeviceStore
-from synapse.storage.user_erasure_store import UserErasureStore
-from synapse.util.caches.stream_change_cache import StreamChangeCache
-
-from .account_data import AccountDataStore
-from .appservice import ApplicationServiceStore, ApplicationServiceTransactionStore
-from .client_ips import ClientIpStore
-from .deviceinbox import DeviceInboxStore
-from .directory import DirectoryStore
-from .e2e_room_keys import EndToEndRoomKeyStore
-from .end_to_end_keys import EndToEndKeyStore
-from .engines import PostgresEngine
-from .event_federation import EventFederationStore
-from .event_push_actions import EventPushActionsStore
-from .events import EventsStore
-from .events_bg_updates import EventsBackgroundUpdatesStore
-from .filtering import FilteringStore
-from .group_server import GroupServerStore
-from .keys import KeyStore
-from .media_repository import MediaRepositoryStore
-from .monthly_active_users import MonthlyActiveUsersStore
-from .openid import OpenIdStore
-from .presence import PresenceStore, UserPresenceState
-from .profile import ProfileStore
-from .push_rule import PushRuleStore
-from .pusher import PusherStore
-from .receipts import ReceiptsStore
-from .registration import RegistrationStore
-from .rejections import RejectionsStore
-from .relations import RelationsStore
-from .room import RoomStore
-from .roommember import RoomMemberStore
-from .search import SearchStore
-from .signatures import SignatureStore
-from .state import StateStore
-from .stats import StatsStore
-from .stream import StreamStore
-from .tags import TagsStore
-from .transactions import TransactionStore
-from .user_directory import UserDirectoryStore
-from .util.id_generators import ChainedIdGenerator, IdGenerator, StreamIdGenerator
-
-logger = logging.getLogger(__name__)
-
-
-class DataStore(
-    EventsBackgroundUpdatesStore,
-    RoomMemberStore,
-    RoomStore,
-    RegistrationStore,
-    StreamStore,
-    ProfileStore,
-    PresenceStore,
-    TransactionStore,
-    DirectoryStore,
-    KeyStore,
-    StateStore,
-    SignatureStore,
-    ApplicationServiceStore,
-    EventsStore,
-    EventFederationStore,
-    MediaRepositoryStore,
-    RejectionsStore,
-    FilteringStore,
-    PusherStore,
-    PushRuleStore,
-    ApplicationServiceTransactionStore,
-    ReceiptsStore,
-    EndToEndKeyStore,
-    EndToEndRoomKeyStore,
-    SearchStore,
-    TagsStore,
-    AccountDataStore,
-    EventPushActionsStore,
-    OpenIdStore,
-    ClientIpStore,
-    DeviceStore,
-    DeviceInboxStore,
-    UserDirectoryStore,
-    GroupServerStore,
-    UserErasureStore,
-    MonthlyActiveUsersStore,
-    StatsStore,
-    RelationsStore,
-):
-    def __init__(self, db_conn, hs):
-        self.hs = hs
-        self._clock = hs.get_clock()
-        self.database_engine = hs.database_engine
-
-        self._stream_id_gen = StreamIdGenerator(
-            db_conn,
-            "events",
-            "stream_ordering",
-            extra_tables=[("local_invites", "stream_id")],
-        )
-        self._backfill_id_gen = StreamIdGenerator(
-            db_conn,
-            "events",
-            "stream_ordering",
-            step=-1,
-            extra_tables=[("ex_outlier_stream", "event_stream_ordering")],
-        )
-        self._presence_id_gen = StreamIdGenerator(
-            db_conn, "presence_stream", "stream_id"
-        )
-        self._device_inbox_id_gen = StreamIdGenerator(
-            db_conn, "device_max_stream_id", "stream_id"
-        )
-        self._public_room_id_gen = StreamIdGenerator(
-            db_conn, "public_room_list_stream", "stream_id"
-        )
-        self._device_list_id_gen = StreamIdGenerator(
-            db_conn, "device_lists_stream", "stream_id"
-        )
-        self._cross_signing_id_gen = StreamIdGenerator(
-            db_conn, "e2e_cross_signing_keys", "stream_id"
-        )
-
-        self._access_tokens_id_gen = IdGenerator(db_conn, "access_tokens", "id")
-        self._event_reports_id_gen = IdGenerator(db_conn, "event_reports", "id")
-        self._push_rule_id_gen = IdGenerator(db_conn, "push_rules", "id")
-        self._push_rules_enable_id_gen = IdGenerator(db_conn, "push_rules_enable", "id")
-        self._push_rules_stream_id_gen = ChainedIdGenerator(
-            self._stream_id_gen, db_conn, "push_rules_stream", "stream_id"
-        )
-        self._pushers_id_gen = StreamIdGenerator(
-            db_conn, "pushers", "id", extra_tables=[("deleted_pushers", "stream_id")]
-        )
-        self._group_updates_id_gen = StreamIdGenerator(
-            db_conn, "local_group_updates", "stream_id"
-        )
-
-        if isinstance(self.database_engine, PostgresEngine):
-            self._cache_id_gen = StreamIdGenerator(
-                db_conn, "cache_invalidation_stream", "stream_id"
-            )
-        else:
-            self._cache_id_gen = None
-
-        self._presence_on_startup = self._get_active_presence(db_conn)
-
-        presence_cache_prefill, min_presence_val = self._get_cache_dict(
-            db_conn,
-            "presence_stream",
-            entity_column="user_id",
-            stream_column="stream_id",
-            max_value=self._presence_id_gen.get_current_token(),
-        )
-        self.presence_stream_cache = StreamChangeCache(
-            "PresenceStreamChangeCache",
-            min_presence_val,
-            prefilled_cache=presence_cache_prefill,
-        )
-
-        max_device_inbox_id = self._device_inbox_id_gen.get_current_token()
-        device_inbox_prefill, min_device_inbox_id = self._get_cache_dict(
-            db_conn,
-            "device_inbox",
-            entity_column="user_id",
-            stream_column="stream_id",
-            max_value=max_device_inbox_id,
-            limit=1000,
-        )
-        self._device_inbox_stream_cache = StreamChangeCache(
-            "DeviceInboxStreamChangeCache",
-            min_device_inbox_id,
-            prefilled_cache=device_inbox_prefill,
-        )
-        # The federation outbox and the local device inbox uses the same
-        # stream_id generator.
-        device_outbox_prefill, min_device_outbox_id = self._get_cache_dict(
-            db_conn,
-            "device_federation_outbox",
-            entity_column="destination",
-            stream_column="stream_id",
-            max_value=max_device_inbox_id,
-            limit=1000,
-        )
-        self._device_federation_outbox_stream_cache = StreamChangeCache(
-            "DeviceFederationOutboxStreamChangeCache",
-            min_device_outbox_id,
-            prefilled_cache=device_outbox_prefill,
-        )
-
-        device_list_max = self._device_list_id_gen.get_current_token()
-        self._device_list_stream_cache = StreamChangeCache(
-            "DeviceListStreamChangeCache", device_list_max
-        )
-        self._user_signature_stream_cache = StreamChangeCache(
-            "UserSignatureStreamChangeCache", device_list_max
-        )
-        self._device_list_federation_stream_cache = StreamChangeCache(
-            "DeviceListFederationStreamChangeCache", device_list_max
-        )
-
-        events_max = self._stream_id_gen.get_current_token()
-        curr_state_delta_prefill, min_curr_state_delta_id = self._get_cache_dict(
-            db_conn,
-            "current_state_delta_stream",
-            entity_column="room_id",
-            stream_column="stream_id",
-            max_value=events_max,  # As we share the stream id with events token
-            limit=1000,
-        )
-        self._curr_state_delta_stream_cache = StreamChangeCache(
-            "_curr_state_delta_stream_cache",
-            min_curr_state_delta_id,
-            prefilled_cache=curr_state_delta_prefill,
-        )
-
-        _group_updates_prefill, min_group_updates_id = self._get_cache_dict(
-            db_conn,
-            "local_group_updates",
-            entity_column="user_id",
-            stream_column="stream_id",
-            max_value=self._group_updates_id_gen.get_current_token(),
-            limit=1000,
-        )
-        self._group_updates_stream_cache = StreamChangeCache(
-            "_group_updates_stream_cache",
-            min_group_updates_id,
-            prefilled_cache=_group_updates_prefill,
-        )
-
-        self._stream_order_on_start = self.get_room_max_stream_ordering()
-        self._min_stream_order_on_start = self.get_room_min_stream_ordering()
-
-        # Used in _generate_user_daily_visits to keep track of progress
-        self._last_user_visit_update = self._get_start_of_day()
-
-        super(DataStore, self).__init__(db_conn, hs)
-
-    def take_presence_startup_info(self):
-        active_on_startup = self._presence_on_startup
-        self._presence_on_startup = None
-        return active_on_startup
-
-    def _get_active_presence(self, db_conn):
-        """Fetch non-offline presence from the database so that we can register
-        the appropriate time outs.
-        """
-
-        sql = (
-            "SELECT user_id, state, last_active_ts, last_federation_update_ts,"
-            " last_user_sync_ts, status_msg, currently_active FROM presence_stream"
-            " WHERE state != ?"
-        )
-        sql = self.database_engine.convert_param_style(sql)
-
-        txn = db_conn.cursor()
-        txn.execute(sql, (PresenceState.OFFLINE,))
-        rows = self.cursor_to_dict(txn)
-        txn.close()
-
-        for row in rows:
-            row["currently_active"] = bool(row["currently_active"])
-
-        return [UserPresenceState(**row) for row in rows]
-
-    def count_daily_users(self):
-        """
-        Counts the number of users who used this homeserver in the last 24 hours.
-        """
-        yesterday = int(self._clock.time_msec()) - (1000 * 60 * 60 * 24)
-        return self.runInteraction("count_daily_users", self._count_users, yesterday)
-
-    def count_monthly_users(self):
-        """
-        Counts the number of users who used this homeserver in the last 30 days.
-        Note this method is intended for phonehome metrics only and is different
-        from the mau figure in synapse.storage.monthly_active_users which,
-        amongst other things, includes a 3 day grace period before a user counts.
-        """
-        thirty_days_ago = int(self._clock.time_msec()) - (1000 * 60 * 60 * 24 * 30)
-        return self.runInteraction(
-            "count_monthly_users", self._count_users, thirty_days_ago
-        )
-
-    def _count_users(self, txn, time_from):
-        """
-        Returns number of users seen in the past time_from period
-        """
-        sql = """
-            SELECT COALESCE(count(*), 0) FROM (
-                SELECT user_id FROM user_ips
-                WHERE last_seen > ?
-                GROUP BY user_id
-            ) u
-        """
-        txn.execute(sql, (time_from,))
-        count, = txn.fetchone()
-        return count
-
-    def count_r30_users(self):
-        """
-        Counts the number of 30 day retained users, defined as:-
-         * Users who have created their accounts more than 30 days ago
-         * Where last seen at most 30 days ago
-         * Where account creation and last_seen are > 30 days apart
-
-         Returns counts globaly for a given user as well as breaking
-         by platform
-        """
-
-        def _count_r30_users(txn):
-            thirty_days_in_secs = 86400 * 30
-            now = int(self._clock.time())
-            thirty_days_ago_in_secs = now - thirty_days_in_secs
-
-            sql = """
-                SELECT platform, COALESCE(count(*), 0) FROM (
-                     SELECT
-                        users.name, platform, users.creation_ts * 1000,
-                        MAX(uip.last_seen)
-                     FROM users
-                     INNER JOIN (
-                         SELECT
-                         user_id,
-                         last_seen,
-                         CASE
-                             WHEN user_agent LIKE '%%Android%%' THEN 'android'
-                             WHEN user_agent LIKE '%%iOS%%' THEN 'ios'
-                             WHEN user_agent LIKE '%%Electron%%' THEN 'electron'
-                             WHEN user_agent LIKE '%%Mozilla%%' THEN 'web'
-                             WHEN user_agent LIKE '%%Gecko%%' THEN 'web'
-                             ELSE 'unknown'
-                         END
-                         AS platform
-                         FROM user_ips
-                     ) uip
-                     ON users.name = uip.user_id
-                     AND users.appservice_id is NULL
-                     AND users.creation_ts < ?
-                     AND uip.last_seen/1000 > ?
-                     AND (uip.last_seen/1000) - users.creation_ts > 86400 * 30
-                     GROUP BY users.name, platform, users.creation_ts
-                ) u GROUP BY platform
-            """
-
-            results = {}
-            txn.execute(sql, (thirty_days_ago_in_secs, thirty_days_ago_in_secs))
-
-            for row in txn:
-                if row[0] == "unknown":
-                    pass
-                results[row[0]] = row[1]
-
-            sql = """
-                SELECT COALESCE(count(*), 0) FROM (
-                    SELECT users.name, users.creation_ts * 1000,
-                                                        MAX(uip.last_seen)
-                    FROM users
-                    INNER JOIN (
-                        SELECT
-                        user_id,
-                        last_seen
-                        FROM user_ips
-                    ) uip
-                    ON users.name = uip.user_id
-                    AND appservice_id is NULL
-                    AND users.creation_ts < ?
-                    AND uip.last_seen/1000 > ?
-                    AND (uip.last_seen/1000) - users.creation_ts > 86400 * 30
-                    GROUP BY users.name, users.creation_ts
-                ) u
-            """
-
-            txn.execute(sql, (thirty_days_ago_in_secs, thirty_days_ago_in_secs))
-
-            count, = txn.fetchone()
-            results["all"] = count
-
-            return results
-
-        return self.runInteraction("count_r30_users", _count_r30_users)
-
-    def _get_start_of_day(self):
-        """
-        Returns millisecond unixtime for start of UTC day.
-        """
-        now = time.gmtime()
-        today_start = calendar.timegm((now.tm_year, now.tm_mon, now.tm_mday, 0, 0, 0))
-        return today_start * 1000
-
-    def generate_user_daily_visits(self):
-        """
-        Generates daily visit data for use in cohort/ retention analysis
-        """
-
-        def _generate_user_daily_visits(txn):
-            logger.info("Calling _generate_user_daily_visits")
-            today_start = self._get_start_of_day()
-            a_day_in_milliseconds = 24 * 60 * 60 * 1000
-            now = self.clock.time_msec()
-
-            sql = """
-                INSERT INTO user_daily_visits (user_id, device_id, timestamp)
-                    SELECT u.user_id, u.device_id, ?
-                    FROM user_ips AS u
-                    LEFT JOIN (
-                      SELECT user_id, device_id, timestamp FROM user_daily_visits
-                      WHERE timestamp = ?
-                    ) udv
-                    ON u.user_id = udv.user_id AND u.device_id=udv.device_id
-                    INNER JOIN users ON users.name=u.user_id
-                    WHERE last_seen > ? AND last_seen <= ?
-                    AND udv.timestamp IS NULL AND users.is_guest=0
-                    AND users.appservice_id IS NULL
-                    GROUP BY u.user_id, u.device_id
-            """
-
-            # This means that the day has rolled over but there could still
-            # be entries from the previous day. There is an edge case
-            # where if the user logs in at 23:59 and overwrites their
-            # last_seen at 00:01 then they will not be counted in the
-            # previous day's stats - it is important that the query is run
-            # often to minimise this case.
-            if today_start > self._last_user_visit_update:
-                yesterday_start = today_start - a_day_in_milliseconds
-                txn.execute(
-                    sql,
-                    (
-                        yesterday_start,
-                        yesterday_start,
-                        self._last_user_visit_update,
-                        today_start,
-                    ),
-                )
-                self._last_user_visit_update = today_start
-
-            txn.execute(
-                sql, (today_start, today_start, self._last_user_visit_update, now)
-            )
-            # Update _last_user_visit_update to now. The reason to do this
-            # rather just clamping to the beginning of the day is to limit
-            # the size of the join - meaning that the query can be run more
-            # frequently
-            self._last_user_visit_update = now
-
-        return self.runInteraction(
-            "generate_user_daily_visits", _generate_user_daily_visits
-        )
-
-    def get_users(self):
-        """Function to reterive a list of users in users table.
-
-        Args:
-        Returns:
-            defer.Deferred: resolves to list[dict[str, Any]]
-        """
-        return self._simple_select_list(
-            table="users",
-            keyvalues={},
-            retcols=["name", "password_hash", "is_guest", "admin", "user_type"],
-            desc="get_users",
-        )
-
-    @defer.inlineCallbacks
-    def get_users_paginate(self, order, start, limit):
-        """Function to reterive a paginated list of users from
-        users list. This will return a json object, which contains
-        list of users and the total number of users in users table.
-
-        Args:
-            order (str): column name to order the select by this column
-            start (int): start number to begin the query from
-            limit (int): number of rows to reterive
-        Returns:
-            defer.Deferred: resolves to json object {list[dict[str, Any]], count}
-        """
-        users = yield self.runInteraction(
-            "get_users_paginate",
-            self._simple_select_list_paginate_txn,
-            table="users",
-            keyvalues={"is_guest": False},
-            orderby=order,
-            start=start,
-            limit=limit,
-            retcols=["name", "password_hash", "is_guest", "admin", "user_type"],
-        )
-        count = yield self.runInteraction("get_users_paginate", self.get_user_count_txn)
-        retval = {"users": users, "total": count}
-        return retval
-
-    def search_users(self, term):
-        """Function to search users list for one or more users with
-        the matched term.
-
-        Args:
-            term (str): search term
-            col (str): column to query term should be matched to
-        Returns:
-            defer.Deferred: resolves to list[dict[str, Any]]
-        """
-        return self._simple_search_list(
-            table="users",
-            term=term,
-            col="name",
-            retcols=["name", "password_hash", "is_guest", "admin", "user_type"],
-            desc="search_users",
-        )
+"""
+The storage layer is split up into multiple parts to allow Synapse to run
+against different configurations of databases (e.g. single or multiple
+databases). The `data_stores` are classes that talk directly to a single
+database and have associated schemas, background updates, etc. On top of those
+there are (or will be) classes that provide high level interfaces that combine
+calls to multiple `data_stores`.
+
+There are also schemas that get applied to every database, regardless of the
+data stores associated with them (e.g. the schema version tables), which are
+stored in `synapse.storage.schema`.
+"""
+
+from synapse.storage.data_stores.main import DataStore  # noqa: F401
 
 
 def are_all_users_on_domain(txn, database_engine, domain):
diff --git a/synapse/storage/data_stores/__init__.py b/synapse/storage/data_stores/__init__.py
new file mode 100644
index 0000000000..56094078ed
--- /dev/null
+++ b/synapse/storage/data_stores/__init__.py
@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
diff --git a/synapse/storage/data_stores/main/__init__.py b/synapse/storage/data_stores/main/__init__.py
new file mode 100644
index 0000000000..b185ba0b3e
--- /dev/null
+++ b/synapse/storage/data_stores/main/__init__.py
@@ -0,0 +1,530 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2018 New Vector Ltd
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import calendar
+import logging
+import time
+
+from twisted.internet import defer
+
+from synapse.api.constants import PresenceState
+from synapse.storage.engines import PostgresEngine
+from synapse.storage.util.id_generators import (
+    ChainedIdGenerator,
+    IdGenerator,
+    StreamIdGenerator,
+)
+from synapse.util.caches.stream_change_cache import StreamChangeCache
+
+from .account_data import AccountDataStore
+from .appservice import ApplicationServiceStore, ApplicationServiceTransactionStore
+from .client_ips import ClientIpStore
+from .deviceinbox import DeviceInboxStore
+from .devices import DeviceStore
+from .directory import DirectoryStore
+from .e2e_room_keys import EndToEndRoomKeyStore
+from .end_to_end_keys import EndToEndKeyStore
+from .event_federation import EventFederationStore
+from .event_push_actions import EventPushActionsStore
+from .events import EventsStore
+from .events_bg_updates import EventsBackgroundUpdatesStore
+from .filtering import FilteringStore
+from .group_server import GroupServerStore
+from .keys import KeyStore
+from .media_repository import MediaRepositoryStore
+from .monthly_active_users import MonthlyActiveUsersStore
+from .openid import OpenIdStore
+from .presence import PresenceStore, UserPresenceState
+from .profile import ProfileStore
+from .push_rule import PushRuleStore
+from .pusher import PusherStore
+from .receipts import ReceiptsStore
+from .registration import RegistrationStore
+from .rejections import RejectionsStore
+from .relations import RelationsStore
+from .room import RoomStore
+from .roommember import RoomMemberStore
+from .search import SearchStore
+from .signatures import SignatureStore
+from .state import StateStore
+from .stats import StatsStore
+from .stream import StreamStore
+from .tags import TagsStore
+from .transactions import TransactionStore
+from .user_directory import UserDirectoryStore
+from .user_erasure_store import UserErasureStore
+
+logger = logging.getLogger(__name__)
+
+
+class DataStore(
+    EventsBackgroundUpdatesStore,
+    RoomMemberStore,
+    RoomStore,
+    RegistrationStore,
+    StreamStore,
+    ProfileStore,
+    PresenceStore,
+    TransactionStore,
+    DirectoryStore,
+    KeyStore,
+    StateStore,
+    SignatureStore,
+    ApplicationServiceStore,
+    EventsStore,
+    EventFederationStore,
+    MediaRepositoryStore,
+    RejectionsStore,
+    FilteringStore,
+    PusherStore,
+    PushRuleStore,
+    ApplicationServiceTransactionStore,
+    ReceiptsStore,
+    EndToEndKeyStore,
+    EndToEndRoomKeyStore,
+    SearchStore,
+    TagsStore,
+    AccountDataStore,
+    EventPushActionsStore,
+    OpenIdStore,
+    ClientIpStore,
+    DeviceStore,
+    DeviceInboxStore,
+    UserDirectoryStore,
+    GroupServerStore,
+    UserErasureStore,
+    MonthlyActiveUsersStore,
+    StatsStore,
+    RelationsStore,
+):
+    def __init__(self, db_conn, hs):
+        self.hs = hs
+        self._clock = hs.get_clock()
+        self.database_engine = hs.database_engine
+
+        self._stream_id_gen = StreamIdGenerator(
+            db_conn,
+            "events",
+            "stream_ordering",
+            extra_tables=[("local_invites", "stream_id")],
+        )
+        self._backfill_id_gen = StreamIdGenerator(
+            db_conn,
+            "events",
+            "stream_ordering",
+            step=-1,
+            extra_tables=[("ex_outlier_stream", "event_stream_ordering")],
+        )
+        self._presence_id_gen = StreamIdGenerator(
+            db_conn, "presence_stream", "stream_id"
+        )
+        self._device_inbox_id_gen = StreamIdGenerator(
+            db_conn, "device_max_stream_id", "stream_id"
+        )
+        self._public_room_id_gen = StreamIdGenerator(
+            db_conn, "public_room_list_stream", "stream_id"
+        )
+        self._device_list_id_gen = StreamIdGenerator(
+            db_conn, "device_lists_stream", "stream_id"
+        )
+        self._cross_signing_id_gen = StreamIdGenerator(
+            db_conn, "e2e_cross_signing_keys", "stream_id"
+        )
+
+        self._access_tokens_id_gen = IdGenerator(db_conn, "access_tokens", "id")
+        self._event_reports_id_gen = IdGenerator(db_conn, "event_reports", "id")
+        self._push_rule_id_gen = IdGenerator(db_conn, "push_rules", "id")
+        self._push_rules_enable_id_gen = IdGenerator(db_conn, "push_rules_enable", "id")
+        self._push_rules_stream_id_gen = ChainedIdGenerator(
+            self._stream_id_gen, db_conn, "push_rules_stream", "stream_id"
+        )
+        self._pushers_id_gen = StreamIdGenerator(
+            db_conn, "pushers", "id", extra_tables=[("deleted_pushers", "stream_id")]
+        )
+        self._group_updates_id_gen = StreamIdGenerator(
+            db_conn, "local_group_updates", "stream_id"
+        )
+
+        if isinstance(self.database_engine, PostgresEngine):
+            self._cache_id_gen = StreamIdGenerator(
+                db_conn, "cache_invalidation_stream", "stream_id"
+            )
+        else:
+            self._cache_id_gen = None
+
+        self._presence_on_startup = self._get_active_presence(db_conn)
+
+        presence_cache_prefill, min_presence_val = self._get_cache_dict(
+            db_conn,
+            "presence_stream",
+            entity_column="user_id",
+            stream_column="stream_id",
+            max_value=self._presence_id_gen.get_current_token(),
+        )
+        self.presence_stream_cache = StreamChangeCache(
+            "PresenceStreamChangeCache",
+            min_presence_val,
+            prefilled_cache=presence_cache_prefill,
+        )
+
+        max_device_inbox_id = self._device_inbox_id_gen.get_current_token()
+        device_inbox_prefill, min_device_inbox_id = self._get_cache_dict(
+            db_conn,
+            "device_inbox",
+            entity_column="user_id",
+            stream_column="stream_id",
+            max_value=max_device_inbox_id,
+            limit=1000,
+        )
+        self._device_inbox_stream_cache = StreamChangeCache(
+            "DeviceInboxStreamChangeCache",
+            min_device_inbox_id,
+            prefilled_cache=device_inbox_prefill,
+        )
+        # The federation outbox and the local device inbox uses the same
+        # stream_id generator.
+        device_outbox_prefill, min_device_outbox_id = self._get_cache_dict(
+            db_conn,
+            "device_federation_outbox",
+            entity_column="destination",
+            stream_column="stream_id",
+            max_value=max_device_inbox_id,
+            limit=1000,
+        )
+        self._device_federation_outbox_stream_cache = StreamChangeCache(
+            "DeviceFederationOutboxStreamChangeCache",
+            min_device_outbox_id,
+            prefilled_cache=device_outbox_prefill,
+        )
+
+        device_list_max = self._device_list_id_gen.get_current_token()
+        self._device_list_stream_cache = StreamChangeCache(
+            "DeviceListStreamChangeCache", device_list_max
+        )
+        self._user_signature_stream_cache = StreamChangeCache(
+            "UserSignatureStreamChangeCache", device_list_max
+        )
+        self._device_list_federation_stream_cache = StreamChangeCache(
+            "DeviceListFederationStreamChangeCache", device_list_max
+        )
+
+        events_max = self._stream_id_gen.get_current_token()
+        curr_state_delta_prefill, min_curr_state_delta_id = self._get_cache_dict(
+            db_conn,
+            "current_state_delta_stream",
+            entity_column="room_id",
+            stream_column="stream_id",
+            max_value=events_max,  # As we share the stream id with events token
+            limit=1000,
+        )
+        self._curr_state_delta_stream_cache = StreamChangeCache(
+            "_curr_state_delta_stream_cache",
+            min_curr_state_delta_id,
+            prefilled_cache=curr_state_delta_prefill,
+        )
+
+        _group_updates_prefill, min_group_updates_id = self._get_cache_dict(
+            db_conn,
+            "local_group_updates",
+            entity_column="user_id",
+            stream_column="stream_id",
+            max_value=self._group_updates_id_gen.get_current_token(),
+            limit=1000,
+        )
+        self._group_updates_stream_cache = StreamChangeCache(
+            "_group_updates_stream_cache",
+            min_group_updates_id,
+            prefilled_cache=_group_updates_prefill,
+        )
+
+        self._stream_order_on_start = self.get_room_max_stream_ordering()
+        self._min_stream_order_on_start = self.get_room_min_stream_ordering()
+
+        # Used in _generate_user_daily_visits to keep track of progress
+        self._last_user_visit_update = self._get_start_of_day()
+
+        super(DataStore, self).__init__(db_conn, hs)
+
+    def take_presence_startup_info(self):
+        active_on_startup = self._presence_on_startup
+        self._presence_on_startup = None
+        return active_on_startup
+
+    def _get_active_presence(self, db_conn):
+        """Fetch non-offline presence from the database so that we can register
+        the appropriate time outs.
+        """
+
+        sql = (
+            "SELECT user_id, state, last_active_ts, last_federation_update_ts,"
+            " last_user_sync_ts, status_msg, currently_active FROM presence_stream"
+            " WHERE state != ?"
+        )
+        sql = self.database_engine.convert_param_style(sql)
+
+        txn = db_conn.cursor()
+        txn.execute(sql, (PresenceState.OFFLINE,))
+        rows = self.cursor_to_dict(txn)
+        txn.close()
+
+        for row in rows:
+            row["currently_active"] = bool(row["currently_active"])
+
+        return [UserPresenceState(**row) for row in rows]
+
+    def count_daily_users(self):
+        """
+        Counts the number of users who used this homeserver in the last 24 hours.
+        """
+        yesterday = int(self._clock.time_msec()) - (1000 * 60 * 60 * 24)
+        return self.runInteraction("count_daily_users", self._count_users, yesterday)
+
+    def count_monthly_users(self):
+        """
+        Counts the number of users who used this homeserver in the last 30 days.
+        Note this method is intended for phonehome metrics only and is different
+        from the mau figure in synapse.storage.monthly_active_users which,
+        amongst other things, includes a 3 day grace period before a user counts.
+        """
+        thirty_days_ago = int(self._clock.time_msec()) - (1000 * 60 * 60 * 24 * 30)
+        return self.runInteraction(
+            "count_monthly_users", self._count_users, thirty_days_ago
+        )
+
+    def _count_users(self, txn, time_from):
+        """
+        Returns number of users seen in the past time_from period
+        """
+        sql = """
+            SELECT COALESCE(count(*), 0) FROM (
+                SELECT user_id FROM user_ips
+                WHERE last_seen > ?
+                GROUP BY user_id
+            ) u
+        """
+        txn.execute(sql, (time_from,))
+        count, = txn.fetchone()
+        return count
+
+    def count_r30_users(self):
+        """
+        Counts the number of 30 day retained users, defined as:-
+         * Users who have created their accounts more than 30 days ago
+         * Where last seen at most 30 days ago
+         * Where account creation and last_seen are > 30 days apart
+
+         Returns counts globaly for a given user as well as breaking
+         by platform
+        """
+
+        def _count_r30_users(txn):
+            thirty_days_in_secs = 86400 * 30
+            now = int(self._clock.time())
+            thirty_days_ago_in_secs = now - thirty_days_in_secs
+
+            sql = """
+                SELECT platform, COALESCE(count(*), 0) FROM (
+                     SELECT
+                        users.name, platform, users.creation_ts * 1000,
+                        MAX(uip.last_seen)
+                     FROM users
+                     INNER JOIN (
+                         SELECT
+                         user_id,
+                         last_seen,
+                         CASE
+                             WHEN user_agent LIKE '%%Android%%' THEN 'android'
+                             WHEN user_agent LIKE '%%iOS%%' THEN 'ios'
+                             WHEN user_agent LIKE '%%Electron%%' THEN 'electron'
+                             WHEN user_agent LIKE '%%Mozilla%%' THEN 'web'
+                             WHEN user_agent LIKE '%%Gecko%%' THEN 'web'
+                             ELSE 'unknown'
+                         END
+                         AS platform
+                         FROM user_ips
+                     ) uip
+                     ON users.name = uip.user_id
+                     AND users.appservice_id is NULL
+                     AND users.creation_ts < ?
+                     AND uip.last_seen/1000 > ?
+                     AND (uip.last_seen/1000) - users.creation_ts > 86400 * 30
+                     GROUP BY users.name, platform, users.creation_ts
+                ) u GROUP BY platform
+            """
+
+            results = {}
+            txn.execute(sql, (thirty_days_ago_in_secs, thirty_days_ago_in_secs))
+
+            for row in txn:
+                if row[0] == "unknown":
+                    pass
+                results[row[0]] = row[1]
+
+            sql = """
+                SELECT COALESCE(count(*), 0) FROM (
+                    SELECT users.name, users.creation_ts * 1000,
+                                                        MAX(uip.last_seen)
+                    FROM users
+                    INNER JOIN (
+                        SELECT
+                        user_id,
+                        last_seen
+                        FROM user_ips
+                    ) uip
+                    ON users.name = uip.user_id
+                    AND appservice_id is NULL
+                    AND users.creation_ts < ?
+                    AND uip.last_seen/1000 > ?
+                    AND (uip.last_seen/1000) - users.creation_ts > 86400 * 30
+                    GROUP BY users.name, users.creation_ts
+                ) u
+            """
+
+            txn.execute(sql, (thirty_days_ago_in_secs, thirty_days_ago_in_secs))
+
+            count, = txn.fetchone()
+            results["all"] = count
+
+            return results
+
+        return self.runInteraction("count_r30_users", _count_r30_users)
+
+    def _get_start_of_day(self):
+        """
+        Returns millisecond unixtime for start of UTC day.
+        """
+        now = time.gmtime()
+        today_start = calendar.timegm((now.tm_year, now.tm_mon, now.tm_mday, 0, 0, 0))
+        return today_start * 1000
+
+    def generate_user_daily_visits(self):
+        """
+        Generates daily visit data for use in cohort/ retention analysis
+        """
+
+        def _generate_user_daily_visits(txn):
+            logger.info("Calling _generate_user_daily_visits")
+            today_start = self._get_start_of_day()
+            a_day_in_milliseconds = 24 * 60 * 60 * 1000
+            now = self.clock.time_msec()
+
+            sql = """
+                INSERT INTO user_daily_visits (user_id, device_id, timestamp)
+                    SELECT u.user_id, u.device_id, ?
+                    FROM user_ips AS u
+                    LEFT JOIN (
+                      SELECT user_id, device_id, timestamp FROM user_daily_visits
+                      WHERE timestamp = ?
+                    ) udv
+                    ON u.user_id = udv.user_id AND u.device_id=udv.device_id
+                    INNER JOIN users ON users.name=u.user_id
+                    WHERE last_seen > ? AND last_seen <= ?
+                    AND udv.timestamp IS NULL AND users.is_guest=0
+                    AND users.appservice_id IS NULL
+                    GROUP BY u.user_id, u.device_id
+            """
+
+            # This means that the day has rolled over but there could still
+            # be entries from the previous day. There is an edge case
+            # where if the user logs in at 23:59 and overwrites their
+            # last_seen at 00:01 then they will not be counted in the
+            # previous day's stats - it is important that the query is run
+            # often to minimise this case.
+            if today_start > self._last_user_visit_update:
+                yesterday_start = today_start - a_day_in_milliseconds
+                txn.execute(
+                    sql,
+                    (
+                        yesterday_start,
+                        yesterday_start,
+                        self._last_user_visit_update,
+                        today_start,
+                    ),
+                )
+                self._last_user_visit_update = today_start
+
+            txn.execute(
+                sql, (today_start, today_start, self._last_user_visit_update, now)
+            )
+            # Update _last_user_visit_update to now. The reason to do this
+            # rather just clamping to the beginning of the day is to limit
+            # the size of the join - meaning that the query can be run more
+            # frequently
+            self._last_user_visit_update = now
+
+        return self.runInteraction(
+            "generate_user_daily_visits", _generate_user_daily_visits
+        )
+
+    def get_users(self):
+        """Function to reterive a list of users in users table.
+
+        Args:
+        Returns:
+            defer.Deferred: resolves to list[dict[str, Any]]
+        """
+        return self._simple_select_list(
+            table="users",
+            keyvalues={},
+            retcols=["name", "password_hash", "is_guest", "admin", "user_type"],
+            desc="get_users",
+        )
+
+    @defer.inlineCallbacks
+    def get_users_paginate(self, order, start, limit):
+        """Function to reterive a paginated list of users from
+        users list. This will return a json object, which contains
+        list of users and the total number of users in users table.
+
+        Args:
+            order (str): column name to order the select by this column
+            start (int): start number to begin the query from
+            limit (int): number of rows to reterive
+        Returns:
+            defer.Deferred: resolves to json object {list[dict[str, Any]], count}
+        """
+        users = yield self.runInteraction(
+            "get_users_paginate",
+            self._simple_select_list_paginate_txn,
+            table="users",
+            keyvalues={"is_guest": False},
+            orderby=order,
+            start=start,
+            limit=limit,
+            retcols=["name", "password_hash", "is_guest", "admin", "user_type"],
+        )
+        count = yield self.runInteraction("get_users_paginate", self.get_user_count_txn)
+        retval = {"users": users, "total": count}
+        return retval
+
+    def search_users(self, term):
+        """Function to search users list for one or more users with
+        the matched term.
+
+        Args:
+            term (str): search term
+            col (str): column to query term should be matched to
+        Returns:
+            defer.Deferred: resolves to list[dict[str, Any]]
+        """
+        return self._simple_search_list(
+            table="users",
+            term=term,
+            col="name",
+            retcols=["name", "password_hash", "is_guest", "admin", "user_type"],
+            desc="search_users",
+        )
diff --git a/synapse/storage/account_data.py b/synapse/storage/data_stores/main/account_data.py
index 6afbfc0d74..6afbfc0d74 100644
--- a/synapse/storage/account_data.py
+++ b/synapse/storage/data_stores/main/account_data.py
diff --git a/synapse/storage/appservice.py b/synapse/storage/data_stores/main/appservice.py
index 435b2acd4d..81babf2029 100644
--- a/synapse/storage/appservice.py
+++ b/synapse/storage/data_stores/main/appservice.py
@@ -22,9 +22,8 @@ from twisted.internet import defer
 
 from synapse.appservice import AppServiceTransaction
 from synapse.config.appservice import load_appservices
-from synapse.storage.events_worker import EventsWorkerStore
-
-from ._base import SQLBaseStore
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
 
 logger = logging.getLogger(__name__)
 
diff --git a/synapse/storage/client_ips.py b/synapse/storage/data_stores/main/client_ips.py
index 067820a5da..706c6a1f3f 100644
--- a/synapse/storage/client_ips.py
+++ b/synapse/storage/data_stores/main/client_ips.py
@@ -20,11 +20,10 @@ from six import iteritems
 from twisted.internet import defer
 
 from synapse.metrics.background_process_metrics import wrap_as_background_process
+from synapse.storage import background_updates
+from synapse.storage._base import Cache
 from synapse.util.caches import CACHE_SIZE_FACTOR
 
-from . import background_updates
-from ._base import Cache
-
 logger = logging.getLogger(__name__)
 
 # Number of msec of granularity to store the user IP 'last seen' time. Smaller
diff --git a/synapse/storage/deviceinbox.py b/synapse/storage/data_stores/main/deviceinbox.py
index f04aad0743..f04aad0743 100644
--- a/synapse/storage/deviceinbox.py
+++ b/synapse/storage/data_stores/main/deviceinbox.py
diff --git a/synapse/storage/devices.py b/synapse/storage/data_stores/main/devices.py
index 6ac165068e..6ac165068e 100644
--- a/synapse/storage/devices.py
+++ b/synapse/storage/data_stores/main/devices.py
diff --git a/synapse/storage/directory.py b/synapse/storage/data_stores/main/directory.py
index eed7757ed5..297966d9f4 100644
--- a/synapse/storage/directory.py
+++ b/synapse/storage/data_stores/main/directory.py
@@ -18,10 +18,9 @@ from collections import namedtuple
 from twisted.internet import defer
 
 from synapse.api.errors import SynapseError
+from synapse.storage._base import SQLBaseStore
 from synapse.util.caches.descriptors import cached
 
-from ._base import SQLBaseStore
-
 RoomAliasMapping = namedtuple("RoomAliasMapping", ("room_id", "room_alias", "servers"))
 
 
diff --git a/synapse/storage/e2e_room_keys.py b/synapse/storage/data_stores/main/e2e_room_keys.py
index be2fe2bab6..ef88e79293 100644
--- a/synapse/storage/e2e_room_keys.py
+++ b/synapse/storage/data_stores/main/e2e_room_keys.py
@@ -19,8 +19,7 @@ from twisted.internet import defer
 
 from synapse.api.errors import StoreError
 from synapse.logging.opentracing import log_kv, trace
-
-from ._base import SQLBaseStore
+from synapse.storage._base import SQLBaseStore
 
 
 class EndToEndRoomKeyStore(SQLBaseStore):
diff --git a/synapse/storage/end_to_end_keys.py b/synapse/storage/data_stores/main/end_to_end_keys.py
index f9bef14992..a0bc6f2d18 100644
--- a/synapse/storage/end_to_end_keys.py
+++ b/synapse/storage/data_stores/main/end_to_end_keys.py
@@ -21,10 +21,9 @@ from canonicaljson import encode_canonical_json, json
 from twisted.internet import defer
 
 from synapse.logging.opentracing import log_kv, set_tag, trace
+from synapse.storage._base import SQLBaseStore, db_to_json
 from synapse.util.caches.descriptors import cached
 
-from ._base import SQLBaseStore, db_to_json
-
 
 class EndToEndKeyWorkerStore(SQLBaseStore):
     @trace
diff --git a/synapse/storage/event_federation.py b/synapse/storage/data_stores/main/event_federation.py
index 47cc10d32a..a470a48e0f 100644
--- a/synapse/storage/event_federation.py
+++ b/synapse/storage/data_stores/main/event_federation.py
@@ -26,8 +26,8 @@ from twisted.internet import defer
 from synapse.api.errors import StoreError
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage._base import SQLBaseStore, make_in_list_sql_clause
-from synapse.storage.events_worker import EventsWorkerStore
-from synapse.storage.signatures import SignatureWorkerStore
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
+from synapse.storage.data_stores.main.signatures import SignatureWorkerStore
 from synapse.util.caches.descriptors import cached
 
 logger = logging.getLogger(__name__)
diff --git a/synapse/storage/event_push_actions.py b/synapse/storage/data_stores/main/event_push_actions.py
index 22025effbc..22025effbc 100644
--- a/synapse/storage/event_push_actions.py
+++ b/synapse/storage/data_stores/main/event_push_actions.py
diff --git a/synapse/storage/events.py b/synapse/storage/data_stores/main/events.py
index ee49ef235d..03b5111c5d 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/data_stores/main/events.py
@@ -41,9 +41,9 @@ from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.state import StateResolutionStore
 from synapse.storage._base import make_in_list_sql_clause
 from synapse.storage.background_updates import BackgroundUpdateStore
-from synapse.storage.event_federation import EventFederationStore
-from synapse.storage.events_worker import EventsWorkerStore
-from synapse.storage.state import StateGroupWorkerStore
+from synapse.storage.data_stores.main.event_federation import EventFederationStore
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
+from synapse.storage.data_stores.main.state import StateGroupWorkerStore
 from synapse.types import RoomStreamToken, get_domain_from_id
 from synapse.util import batch_iter
 from synapse.util.async_helpers import ObservableDeferred
diff --git a/synapse/storage/events_bg_updates.py b/synapse/storage/data_stores/main/events_bg_updates.py
index 31ea6f917f..31ea6f917f 100644
--- a/synapse/storage/events_bg_updates.py
+++ b/synapse/storage/data_stores/main/events_bg_updates.py
diff --git a/synapse/storage/events_worker.py b/synapse/storage/data_stores/main/events_worker.py
index 4c4b76bd93..4c4b76bd93 100644
--- a/synapse/storage/events_worker.py
+++ b/synapse/storage/data_stores/main/events_worker.py
diff --git a/synapse/storage/filtering.py b/synapse/storage/data_stores/main/filtering.py
index 7c2a7da836..a2a2a67927 100644
--- a/synapse/storage/filtering.py
+++ b/synapse/storage/data_stores/main/filtering.py
@@ -16,10 +16,9 @@
 from canonicaljson import encode_canonical_json
 
 from synapse.api.errors import Codes, SynapseError
+from synapse.storage._base import SQLBaseStore, db_to_json
 from synapse.util.caches.descriptors import cachedInlineCallbacks
 
-from ._base import SQLBaseStore, db_to_json
-
 
 class FilteringStore(SQLBaseStore):
     @cachedInlineCallbacks(num_args=2)
diff --git a/synapse/storage/group_server.py b/synapse/storage/data_stores/main/group_server.py
index 15b01c6958..aeae5a2b28 100644
--- a/synapse/storage/group_server.py
+++ b/synapse/storage/data_stores/main/group_server.py
@@ -19,8 +19,7 @@ from canonicaljson import json
 from twisted.internet import defer
 
 from synapse.api.errors import SynapseError
-
-from ._base import SQLBaseStore
+from synapse.storage._base import SQLBaseStore
 
 # The category ID for the "default" category. We don't store as null in the
 # database to avoid the fun of null != null
diff --git a/synapse/storage/data_stores/main/keys.py b/synapse/storage/data_stores/main/keys.py
new file mode 100644
index 0000000000..ebc7db3ed6
--- /dev/null
+++ b/synapse/storage/data_stores/main/keys.py
@@ -0,0 +1,214 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2019 New Vector Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import itertools
+import logging
+
+import six
+
+from signedjson.key import decode_verify_key_bytes
+
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.keys import FetchKeyResult
+from synapse.util import batch_iter
+from synapse.util.caches.descriptors import cached, cachedList
+
+logger = logging.getLogger(__name__)
+
+# py2 sqlite has buffer hardcoded as only binary type, so we must use it,
+# despite being deprecated and removed in favor of memoryview
+if six.PY2:
+    db_binary_type = six.moves.builtins.buffer
+else:
+    db_binary_type = memoryview
+
+
+class KeyStore(SQLBaseStore):
+    """Persistence for signature verification keys
+    """
+
+    @cached()
+    def _get_server_verify_key(self, server_name_and_key_id):
+        raise NotImplementedError()
+
+    @cachedList(
+        cached_method_name="_get_server_verify_key", list_name="server_name_and_key_ids"
+    )
+    def get_server_verify_keys(self, server_name_and_key_ids):
+        """
+        Args:
+            server_name_and_key_ids (iterable[Tuple[str, str]]):
+                iterable of (server_name, key-id) tuples to fetch keys for
+
+        Returns:
+            Deferred: resolves to dict[Tuple[str, str], FetchKeyResult|None]:
+                map from (server_name, key_id) -> FetchKeyResult, or None if the key is
+                unknown
+        """
+        keys = {}
+
+        def _get_keys(txn, batch):
+            """Processes a batch of keys to fetch, and adds the result to `keys`."""
+
+            # batch_iter always returns tuples so it's safe to do len(batch)
+            sql = (
+                "SELECT server_name, key_id, verify_key, ts_valid_until_ms "
+                "FROM server_signature_keys WHERE 1=0"
+            ) + " OR (server_name=? AND key_id=?)" * len(batch)
+
+            txn.execute(sql, tuple(itertools.chain.from_iterable(batch)))
+
+            for row in txn:
+                server_name, key_id, key_bytes, ts_valid_until_ms = row
+
+                if ts_valid_until_ms is None:
+                    # Old keys may be stored with a ts_valid_until_ms of null,
+                    # in which case we treat this as if it was set to `0`, i.e.
+                    # it won't match key requests that define a minimum
+                    # `ts_valid_until_ms`.
+                    ts_valid_until_ms = 0
+
+                res = FetchKeyResult(
+                    verify_key=decode_verify_key_bytes(key_id, bytes(key_bytes)),
+                    valid_until_ts=ts_valid_until_ms,
+                )
+                keys[(server_name, key_id)] = res
+
+        def _txn(txn):
+            for batch in batch_iter(server_name_and_key_ids, 50):
+                _get_keys(txn, batch)
+            return keys
+
+        return self.runInteraction("get_server_verify_keys", _txn)
+
+    def store_server_verify_keys(self, from_server, ts_added_ms, verify_keys):
+        """Stores NACL verification keys for remote servers.
+        Args:
+            from_server (str): Where the verification keys were looked up
+            ts_added_ms (int): The time to record that the key was added
+            verify_keys (iterable[tuple[str, str, FetchKeyResult]]):
+                keys to be stored. Each entry is a triplet of
+                (server_name, key_id, key).
+        """
+        key_values = []
+        value_values = []
+        invalidations = []
+        for server_name, key_id, fetch_result in verify_keys:
+            key_values.append((server_name, key_id))
+            value_values.append(
+                (
+                    from_server,
+                    ts_added_ms,
+                    fetch_result.valid_until_ts,
+                    db_binary_type(fetch_result.verify_key.encode()),
+                )
+            )
+            # invalidate takes a tuple corresponding to the params of
+            # _get_server_verify_key. _get_server_verify_key only takes one
+            # param, which is itself the 2-tuple (server_name, key_id).
+            invalidations.append((server_name, key_id))
+
+        def _invalidate(res):
+            f = self._get_server_verify_key.invalidate
+            for i in invalidations:
+                f((i,))
+            return res
+
+        return self.runInteraction(
+            "store_server_verify_keys",
+            self._simple_upsert_many_txn,
+            table="server_signature_keys",
+            key_names=("server_name", "key_id"),
+            key_values=key_values,
+            value_names=(
+                "from_server",
+                "ts_added_ms",
+                "ts_valid_until_ms",
+                "verify_key",
+            ),
+            value_values=value_values,
+        ).addCallback(_invalidate)
+
+    def store_server_keys_json(
+        self, server_name, key_id, from_server, ts_now_ms, ts_expires_ms, key_json_bytes
+    ):
+        """Stores the JSON bytes for a set of keys from a server
+        The JSON should be signed by the originating server, the intermediate
+        server, and by this server. Updates the value for the
+        (server_name, key_id, from_server) triplet if one already existed.
+        Args:
+            server_name (str): The name of the server.
+            key_id (str): The identifer of the key this JSON is for.
+            from_server (str): The server this JSON was fetched from.
+            ts_now_ms (int): The time now in milliseconds.
+            ts_valid_until_ms (int): The time when this json stops being valid.
+            key_json (bytes): The encoded JSON.
+        """
+        return self._simple_upsert(
+            table="server_keys_json",
+            keyvalues={
+                "server_name": server_name,
+                "key_id": key_id,
+                "from_server": from_server,
+            },
+            values={
+                "server_name": server_name,
+                "key_id": key_id,
+                "from_server": from_server,
+                "ts_added_ms": ts_now_ms,
+                "ts_valid_until_ms": ts_expires_ms,
+                "key_json": db_binary_type(key_json_bytes),
+            },
+            desc="store_server_keys_json",
+        )
+
+    def get_server_keys_json(self, server_keys):
+        """Retrive the key json for a list of server_keys and key ids.
+        If no keys are found for a given server, key_id and source then
+        that server, key_id, and source triplet entry will be an empty list.
+        The JSON is returned as a byte array so that it can be efficiently
+        used in an HTTP response.
+        Args:
+            server_keys (list): List of (server_name, key_id, source) triplets.
+        Returns:
+            Deferred[dict[Tuple[str, str, str|None], list[dict]]]:
+                Dict mapping (server_name, key_id, source) triplets to lists of dicts
+        """
+
+        def _get_server_keys_json_txn(txn):
+            results = {}
+            for server_name, key_id, from_server in server_keys:
+                keyvalues = {"server_name": server_name}
+                if key_id is not None:
+                    keyvalues["key_id"] = key_id
+                if from_server is not None:
+                    keyvalues["from_server"] = from_server
+                rows = self._simple_select_list_txn(
+                    txn,
+                    "server_keys_json",
+                    keyvalues=keyvalues,
+                    retcols=(
+                        "key_id",
+                        "from_server",
+                        "ts_added_ms",
+                        "ts_valid_until_ms",
+                        "key_json",
+                    ),
+                )
+                results[(server_name, key_id, from_server)] = rows
+            return results
+
+        return self.runInteraction("get_server_keys_json", _get_server_keys_json_txn)
diff --git a/synapse/storage/media_repository.py b/synapse/storage/data_stores/main/media_repository.py
index 84b5f3ad5e..84b5f3ad5e 100644
--- a/synapse/storage/media_repository.py
+++ b/synapse/storage/data_stores/main/media_repository.py
diff --git a/synapse/storage/monthly_active_users.py b/synapse/storage/data_stores/main/monthly_active_users.py
index 3803604be7..e6ee1e4aaa 100644
--- a/synapse/storage/monthly_active_users.py
+++ b/synapse/storage/data_stores/main/monthly_active_users.py
@@ -16,10 +16,9 @@ import logging
 
 from twisted.internet import defer
 
+from synapse.storage._base import SQLBaseStore
 from synapse.util.caches.descriptors import cached
 
-from ._base import SQLBaseStore
-
 logger = logging.getLogger(__name__)
 
 # Number of msec of granularity to store the monthly_active_user timestamp
diff --git a/synapse/storage/openid.py b/synapse/storage/data_stores/main/openid.py
index b3318045ee..79b40044d9 100644
--- a/synapse/storage/openid.py
+++ b/synapse/storage/data_stores/main/openid.py
@@ -1,4 +1,4 @@
-from ._base import SQLBaseStore
+from synapse.storage._base import SQLBaseStore
 
 
 class OpenIdStore(SQLBaseStore):
diff --git a/synapse/storage/data_stores/main/presence.py b/synapse/storage/data_stores/main/presence.py
new file mode 100644
index 0000000000..523ed6575e
--- /dev/null
+++ b/synapse/storage/data_stores/main/presence.py
@@ -0,0 +1,150 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from twisted.internet import defer
+
+from synapse.storage._base import SQLBaseStore, make_in_list_sql_clause
+from synapse.storage.presence import UserPresenceState
+from synapse.util import batch_iter
+from synapse.util.caches.descriptors import cached, cachedList
+
+
+class PresenceStore(SQLBaseStore):
+    @defer.inlineCallbacks
+    def update_presence(self, presence_states):
+        stream_ordering_manager = self._presence_id_gen.get_next_mult(
+            len(presence_states)
+        )
+
+        with stream_ordering_manager as stream_orderings:
+            yield self.runInteraction(
+                "update_presence",
+                self._update_presence_txn,
+                stream_orderings,
+                presence_states,
+            )
+
+        return stream_orderings[-1], self._presence_id_gen.get_current_token()
+
+    def _update_presence_txn(self, txn, stream_orderings, presence_states):
+        for stream_id, state in zip(stream_orderings, presence_states):
+            txn.call_after(
+                self.presence_stream_cache.entity_has_changed, state.user_id, stream_id
+            )
+            txn.call_after(self._get_presence_for_user.invalidate, (state.user_id,))
+
+        # Actually insert new rows
+        self._simple_insert_many_txn(
+            txn,
+            table="presence_stream",
+            values=[
+                {
+                    "stream_id": stream_id,
+                    "user_id": state.user_id,
+                    "state": state.state,
+                    "last_active_ts": state.last_active_ts,
+                    "last_federation_update_ts": state.last_federation_update_ts,
+                    "last_user_sync_ts": state.last_user_sync_ts,
+                    "status_msg": state.status_msg,
+                    "currently_active": state.currently_active,
+                }
+                for state in presence_states
+            ],
+        )
+
+        # Delete old rows to stop database from getting really big
+        sql = "DELETE FROM presence_stream WHERE stream_id < ? AND "
+
+        for states in batch_iter(presence_states, 50):
+            clause, args = make_in_list_sql_clause(
+                self.database_engine, "user_id", [s.user_id for s in states]
+            )
+            txn.execute(sql + clause, [stream_id] + list(args))
+
+    def get_all_presence_updates(self, last_id, current_id):
+        if last_id == current_id:
+            return defer.succeed([])
+
+        def get_all_presence_updates_txn(txn):
+            sql = (
+                "SELECT stream_id, user_id, state, last_active_ts,"
+                " last_federation_update_ts, last_user_sync_ts, status_msg,"
+                " currently_active"
+                " FROM presence_stream"
+                " WHERE ? < stream_id AND stream_id <= ?"
+            )
+            txn.execute(sql, (last_id, current_id))
+            return txn.fetchall()
+
+        return self.runInteraction(
+            "get_all_presence_updates", get_all_presence_updates_txn
+        )
+
+    @cached()
+    def _get_presence_for_user(self, user_id):
+        raise NotImplementedError()
+
+    @cachedList(
+        cached_method_name="_get_presence_for_user",
+        list_name="user_ids",
+        num_args=1,
+        inlineCallbacks=True,
+    )
+    def get_presence_for_users(self, user_ids):
+        rows = yield self._simple_select_many_batch(
+            table="presence_stream",
+            column="user_id",
+            iterable=user_ids,
+            keyvalues={},
+            retcols=(
+                "user_id",
+                "state",
+                "last_active_ts",
+                "last_federation_update_ts",
+                "last_user_sync_ts",
+                "status_msg",
+                "currently_active",
+            ),
+            desc="get_presence_for_users",
+        )
+
+        for row in rows:
+            row["currently_active"] = bool(row["currently_active"])
+
+        return {row["user_id"]: UserPresenceState(**row) for row in rows}
+
+    def get_current_presence_token(self):
+        return self._presence_id_gen.get_current_token()
+
+    def allow_presence_visible(self, observed_localpart, observer_userid):
+        return self._simple_insert(
+            table="presence_allow_inbound",
+            values={
+                "observed_user_id": observed_localpart,
+                "observer_user_id": observer_userid,
+            },
+            desc="allow_presence_visible",
+            or_ignore=True,
+        )
+
+    def disallow_presence_visible(self, observed_localpart, observer_userid):
+        return self._simple_delete_one(
+            table="presence_allow_inbound",
+            keyvalues={
+                "observed_user_id": observed_localpart,
+                "observer_user_id": observer_userid,
+            },
+            desc="disallow_presence_visible",
+        )
diff --git a/synapse/storage/profile.py b/synapse/storage/data_stores/main/profile.py
index 912c1df6be..e4e8a1c1d6 100644
--- a/synapse/storage/profile.py
+++ b/synapse/storage/data_stores/main/profile.py
@@ -16,9 +16,8 @@
 from twisted.internet import defer
 
 from synapse.api.errors import StoreError
-from synapse.storage.roommember import ProfileInfo
-
-from ._base import SQLBaseStore
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.data_stores.main.roommember import ProfileInfo
 
 
 class ProfileWorkerStore(SQLBaseStore):
diff --git a/synapse/storage/data_stores/main/push_rule.py b/synapse/storage/data_stores/main/push_rule.py
new file mode 100644
index 0000000000..cd95f1ce60
--- /dev/null
+++ b/synapse/storage/data_stores/main/push_rule.py
@@ -0,0 +1,713 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import abc
+import logging
+
+from canonicaljson import json
+
+from twisted.internet import defer
+
+from synapse.push.baserules import list_with_base_rules
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.data_stores.main.appservice import ApplicationServiceWorkerStore
+from synapse.storage.data_stores.main.pusher import PusherWorkerStore
+from synapse.storage.data_stores.main.receipts import ReceiptsWorkerStore
+from synapse.storage.data_stores.main.roommember import RoomMemberWorkerStore
+from synapse.storage.push_rule import InconsistentRuleException, RuleNotFoundException
+from synapse.util.caches.descriptors import cachedInlineCallbacks, cachedList
+from synapse.util.caches.stream_change_cache import StreamChangeCache
+
+logger = logging.getLogger(__name__)
+
+
+def _load_rules(rawrules, enabled_map):
+    ruleslist = []
+    for rawrule in rawrules:
+        rule = dict(rawrule)
+        rule["conditions"] = json.loads(rawrule["conditions"])
+        rule["actions"] = json.loads(rawrule["actions"])
+        ruleslist.append(rule)
+
+    # We're going to be mutating this a lot, so do a deep copy
+    rules = list(list_with_base_rules(ruleslist))
+
+    for i, rule in enumerate(rules):
+        rule_id = rule["rule_id"]
+        if rule_id in enabled_map:
+            if rule.get("enabled", True) != bool(enabled_map[rule_id]):
+                # Rules are cached across users.
+                rule = dict(rule)
+                rule["enabled"] = bool(enabled_map[rule_id])
+                rules[i] = rule
+
+    return rules
+
+
+class PushRulesWorkerStore(
+    ApplicationServiceWorkerStore,
+    ReceiptsWorkerStore,
+    PusherWorkerStore,
+    RoomMemberWorkerStore,
+    SQLBaseStore,
+):
+    """This is an abstract base class where subclasses must implement
+    `get_max_push_rules_stream_id` which can be called in the initializer.
+    """
+
+    # This ABCMeta metaclass ensures that we cannot be instantiated without
+    # the abstract methods being implemented.
+    __metaclass__ = abc.ABCMeta
+
+    def __init__(self, db_conn, hs):
+        super(PushRulesWorkerStore, self).__init__(db_conn, hs)
+
+        push_rules_prefill, push_rules_id = self._get_cache_dict(
+            db_conn,
+            "push_rules_stream",
+            entity_column="user_id",
+            stream_column="stream_id",
+            max_value=self.get_max_push_rules_stream_id(),
+        )
+
+        self.push_rules_stream_cache = StreamChangeCache(
+            "PushRulesStreamChangeCache",
+            push_rules_id,
+            prefilled_cache=push_rules_prefill,
+        )
+
+    @abc.abstractmethod
+    def get_max_push_rules_stream_id(self):
+        """Get the position of the push rules stream.
+
+        Returns:
+            int
+        """
+        raise NotImplementedError()
+
+    @cachedInlineCallbacks(max_entries=5000)
+    def get_push_rules_for_user(self, user_id):
+        rows = yield self._simple_select_list(
+            table="push_rules",
+            keyvalues={"user_name": user_id},
+            retcols=(
+                "user_name",
+                "rule_id",
+                "priority_class",
+                "priority",
+                "conditions",
+                "actions",
+            ),
+            desc="get_push_rules_enabled_for_user",
+        )
+
+        rows.sort(key=lambda row: (-int(row["priority_class"]), -int(row["priority"])))
+
+        enabled_map = yield self.get_push_rules_enabled_for_user(user_id)
+
+        rules = _load_rules(rows, enabled_map)
+
+        return rules
+
+    @cachedInlineCallbacks(max_entries=5000)
+    def get_push_rules_enabled_for_user(self, user_id):
+        results = yield self._simple_select_list(
+            table="push_rules_enable",
+            keyvalues={"user_name": user_id},
+            retcols=("user_name", "rule_id", "enabled"),
+            desc="get_push_rules_enabled_for_user",
+        )
+        return {r["rule_id"]: False if r["enabled"] == 0 else True for r in results}
+
+    def have_push_rules_changed_for_user(self, user_id, last_id):
+        if not self.push_rules_stream_cache.has_entity_changed(user_id, last_id):
+            return defer.succeed(False)
+        else:
+
+            def have_push_rules_changed_txn(txn):
+                sql = (
+                    "SELECT COUNT(stream_id) FROM push_rules_stream"
+                    " WHERE user_id = ? AND ? < stream_id"
+                )
+                txn.execute(sql, (user_id, last_id))
+                count, = txn.fetchone()
+                return bool(count)
+
+            return self.runInteraction(
+                "have_push_rules_changed", have_push_rules_changed_txn
+            )
+
+    @cachedList(
+        cached_method_name="get_push_rules_for_user",
+        list_name="user_ids",
+        num_args=1,
+        inlineCallbacks=True,
+    )
+    def bulk_get_push_rules(self, user_ids):
+        if not user_ids:
+            return {}
+
+        results = {user_id: [] for user_id in user_ids}
+
+        rows = yield self._simple_select_many_batch(
+            table="push_rules",
+            column="user_name",
+            iterable=user_ids,
+            retcols=("*",),
+            desc="bulk_get_push_rules",
+        )
+
+        rows.sort(key=lambda row: (-int(row["priority_class"]), -int(row["priority"])))
+
+        for row in rows:
+            results.setdefault(row["user_name"], []).append(row)
+
+        enabled_map_by_user = yield self.bulk_get_push_rules_enabled(user_ids)
+
+        for user_id, rules in results.items():
+            results[user_id] = _load_rules(rules, enabled_map_by_user.get(user_id, {}))
+
+        return results
+
+    @defer.inlineCallbacks
+    def copy_push_rule_from_room_to_room(self, new_room_id, user_id, rule):
+        """Copy a single push rule from one room to another for a specific user.
+
+        Args:
+            new_room_id (str): ID of the new room.
+            user_id (str): ID of user the push rule belongs to.
+            rule (Dict): A push rule.
+        """
+        # Create new rule id
+        rule_id_scope = "/".join(rule["rule_id"].split("/")[:-1])
+        new_rule_id = rule_id_scope + "/" + new_room_id
+
+        # Change room id in each condition
+        for condition in rule.get("conditions", []):
+            if condition.get("key") == "room_id":
+                condition["pattern"] = new_room_id
+
+        # Add the rule for the new room
+        yield self.add_push_rule(
+            user_id=user_id,
+            rule_id=new_rule_id,
+            priority_class=rule["priority_class"],
+            conditions=rule["conditions"],
+            actions=rule["actions"],
+        )
+
+    @defer.inlineCallbacks
+    def copy_push_rules_from_room_to_room_for_user(
+        self, old_room_id, new_room_id, user_id
+    ):
+        """Copy all of the push rules from one room to another for a specific
+        user.
+
+        Args:
+            old_room_id (str): ID of the old room.
+            new_room_id (str): ID of the new room.
+            user_id (str): ID of user to copy push rules for.
+        """
+        # Retrieve push rules for this user
+        user_push_rules = yield self.get_push_rules_for_user(user_id)
+
+        # Get rules relating to the old room and copy them to the new room
+        for rule in user_push_rules:
+            conditions = rule.get("conditions", [])
+            if any(
+                (c.get("key") == "room_id" and c.get("pattern") == old_room_id)
+                for c in conditions
+            ):
+                yield self.copy_push_rule_from_room_to_room(new_room_id, user_id, rule)
+
+    @defer.inlineCallbacks
+    def bulk_get_push_rules_for_room(self, event, context):
+        state_group = context.state_group
+        if not state_group:
+            # If state_group is None it means it has yet to be assigned a
+            # state group, i.e. we need to make sure that calls with a state_group
+            # of None don't hit previous cached calls with a None state_group.
+            # To do this we set the state_group to a new object as object() != object()
+            state_group = object()
+
+        current_state_ids = yield context.get_current_state_ids(self)
+        result = yield self._bulk_get_push_rules_for_room(
+            event.room_id, state_group, current_state_ids, event=event
+        )
+        return result
+
+    @cachedInlineCallbacks(num_args=2, cache_context=True)
+    def _bulk_get_push_rules_for_room(
+        self, room_id, state_group, current_state_ids, cache_context, event=None
+    ):
+        # We don't use `state_group`, its there so that we can cache based
+        # on it. However, its important that its never None, since two current_state's
+        # with a state_group of None are likely to be different.
+        # See bulk_get_push_rules_for_room for how we work around this.
+        assert state_group is not None
+
+        # We also will want to generate notifs for other people in the room so
+        # their unread countss are correct in the event stream, but to avoid
+        # generating them for bot / AS users etc, we only do so for people who've
+        # sent a read receipt into the room.
+
+        users_in_room = yield self._get_joined_users_from_context(
+            room_id,
+            state_group,
+            current_state_ids,
+            on_invalidate=cache_context.invalidate,
+            event=event,
+        )
+
+        # We ignore app service users for now. This is so that we don't fill
+        # up the `get_if_users_have_pushers` cache with AS entries that we
+        # know don't have pushers, nor even read receipts.
+        local_users_in_room = set(
+            u
+            for u in users_in_room
+            if self.hs.is_mine_id(u)
+            and not self.get_if_app_services_interested_in_user(u)
+        )
+
+        # users in the room who have pushers need to get push rules run because
+        # that's how their pushers work
+        if_users_with_pushers = yield self.get_if_users_have_pushers(
+            local_users_in_room, on_invalidate=cache_context.invalidate
+        )
+        user_ids = set(
+            uid for uid, have_pusher in if_users_with_pushers.items() if have_pusher
+        )
+
+        users_with_receipts = yield self.get_users_with_read_receipts_in_room(
+            room_id, on_invalidate=cache_context.invalidate
+        )
+
+        # any users with pushers must be ours: they have pushers
+        for uid in users_with_receipts:
+            if uid in local_users_in_room:
+                user_ids.add(uid)
+
+        rules_by_user = yield self.bulk_get_push_rules(
+            user_ids, on_invalidate=cache_context.invalidate
+        )
+
+        rules_by_user = {k: v for k, v in rules_by_user.items() if v is not None}
+
+        return rules_by_user
+
+    @cachedList(
+        cached_method_name="get_push_rules_enabled_for_user",
+        list_name="user_ids",
+        num_args=1,
+        inlineCallbacks=True,
+    )
+    def bulk_get_push_rules_enabled(self, user_ids):
+        if not user_ids:
+            return {}
+
+        results = {user_id: {} for user_id in user_ids}
+
+        rows = yield self._simple_select_many_batch(
+            table="push_rules_enable",
+            column="user_name",
+            iterable=user_ids,
+            retcols=("user_name", "rule_id", "enabled"),
+            desc="bulk_get_push_rules_enabled",
+        )
+        for row in rows:
+            enabled = bool(row["enabled"])
+            results.setdefault(row["user_name"], {})[row["rule_id"]] = enabled
+        return results
+
+
+class PushRuleStore(PushRulesWorkerStore):
+    @defer.inlineCallbacks
+    def add_push_rule(
+        self,
+        user_id,
+        rule_id,
+        priority_class,
+        conditions,
+        actions,
+        before=None,
+        after=None,
+    ):
+        conditions_json = json.dumps(conditions)
+        actions_json = json.dumps(actions)
+        with self._push_rules_stream_id_gen.get_next() as ids:
+            stream_id, event_stream_ordering = ids
+            if before or after:
+                yield self.runInteraction(
+                    "_add_push_rule_relative_txn",
+                    self._add_push_rule_relative_txn,
+                    stream_id,
+                    event_stream_ordering,
+                    user_id,
+                    rule_id,
+                    priority_class,
+                    conditions_json,
+                    actions_json,
+                    before,
+                    after,
+                )
+            else:
+                yield self.runInteraction(
+                    "_add_push_rule_highest_priority_txn",
+                    self._add_push_rule_highest_priority_txn,
+                    stream_id,
+                    event_stream_ordering,
+                    user_id,
+                    rule_id,
+                    priority_class,
+                    conditions_json,
+                    actions_json,
+                )
+
+    def _add_push_rule_relative_txn(
+        self,
+        txn,
+        stream_id,
+        event_stream_ordering,
+        user_id,
+        rule_id,
+        priority_class,
+        conditions_json,
+        actions_json,
+        before,
+        after,
+    ):
+        # Lock the table since otherwise we'll have annoying races between the
+        # SELECT here and the UPSERT below.
+        self.database_engine.lock_table(txn, "push_rules")
+
+        relative_to_rule = before or after
+
+        res = self._simple_select_one_txn(
+            txn,
+            table="push_rules",
+            keyvalues={"user_name": user_id, "rule_id": relative_to_rule},
+            retcols=["priority_class", "priority"],
+            allow_none=True,
+        )
+
+        if not res:
+            raise RuleNotFoundException(
+                "before/after rule not found: %s" % (relative_to_rule,)
+            )
+
+        base_priority_class = res["priority_class"]
+        base_rule_priority = res["priority"]
+
+        if base_priority_class != priority_class:
+            raise InconsistentRuleException(
+                "Given priority class does not match class of relative rule"
+            )
+
+        if before:
+            # Higher priority rules are executed first, So adding a rule before
+            # a rule means giving it a higher priority than that rule.
+            new_rule_priority = base_rule_priority + 1
+        else:
+            # We increment the priority of the existing rules to make space for
+            # the new rule. Therefore if we want this rule to appear after
+            # an existing rule we give it the priority of the existing rule,
+            # and then increment the priority of the existing rule.
+            new_rule_priority = base_rule_priority
+
+        sql = (
+            "UPDATE push_rules SET priority = priority + 1"
+            " WHERE user_name = ? AND priority_class = ? AND priority >= ?"
+        )
+
+        txn.execute(sql, (user_id, priority_class, new_rule_priority))
+
+        self._upsert_push_rule_txn(
+            txn,
+            stream_id,
+            event_stream_ordering,
+            user_id,
+            rule_id,
+            priority_class,
+            new_rule_priority,
+            conditions_json,
+            actions_json,
+        )
+
+    def _add_push_rule_highest_priority_txn(
+        self,
+        txn,
+        stream_id,
+        event_stream_ordering,
+        user_id,
+        rule_id,
+        priority_class,
+        conditions_json,
+        actions_json,
+    ):
+        # Lock the table since otherwise we'll have annoying races between the
+        # SELECT here and the UPSERT below.
+        self.database_engine.lock_table(txn, "push_rules")
+
+        # find the highest priority rule in that class
+        sql = (
+            "SELECT COUNT(*), MAX(priority) FROM push_rules"
+            " WHERE user_name = ? and priority_class = ?"
+        )
+        txn.execute(sql, (user_id, priority_class))
+        res = txn.fetchall()
+        (how_many, highest_prio) = res[0]
+
+        new_prio = 0
+        if how_many > 0:
+            new_prio = highest_prio + 1
+
+        self._upsert_push_rule_txn(
+            txn,
+            stream_id,
+            event_stream_ordering,
+            user_id,
+            rule_id,
+            priority_class,
+            new_prio,
+            conditions_json,
+            actions_json,
+        )
+
+    def _upsert_push_rule_txn(
+        self,
+        txn,
+        stream_id,
+        event_stream_ordering,
+        user_id,
+        rule_id,
+        priority_class,
+        priority,
+        conditions_json,
+        actions_json,
+        update_stream=True,
+    ):
+        """Specialised version of _simple_upsert_txn that picks a push_rule_id
+        using the _push_rule_id_gen if it needs to insert the rule. It assumes
+        that the "push_rules" table is locked"""
+
+        sql = (
+            "UPDATE push_rules"
+            " SET priority_class = ?, priority = ?, conditions = ?, actions = ?"
+            " WHERE user_name = ? AND rule_id = ?"
+        )
+
+        txn.execute(
+            sql,
+            (priority_class, priority, conditions_json, actions_json, user_id, rule_id),
+        )
+
+        if txn.rowcount == 0:
+            # We didn't update a row with the given rule_id so insert one
+            push_rule_id = self._push_rule_id_gen.get_next()
+
+            self._simple_insert_txn(
+                txn,
+                table="push_rules",
+                values={
+                    "id": push_rule_id,
+                    "user_name": user_id,
+                    "rule_id": rule_id,
+                    "priority_class": priority_class,
+                    "priority": priority,
+                    "conditions": conditions_json,
+                    "actions": actions_json,
+                },
+            )
+
+        if update_stream:
+            self._insert_push_rules_update_txn(
+                txn,
+                stream_id,
+                event_stream_ordering,
+                user_id,
+                rule_id,
+                op="ADD",
+                data={
+                    "priority_class": priority_class,
+                    "priority": priority,
+                    "conditions": conditions_json,
+                    "actions": actions_json,
+                },
+            )
+
+    @defer.inlineCallbacks
+    def delete_push_rule(self, user_id, rule_id):
+        """
+        Delete a push rule. Args specify the row to be deleted and can be
+        any of the columns in the push_rule table, but below are the
+        standard ones
+
+        Args:
+            user_id (str): The matrix ID of the push rule owner
+            rule_id (str): The rule_id of the rule to be deleted
+        """
+
+        def delete_push_rule_txn(txn, stream_id, event_stream_ordering):
+            self._simple_delete_one_txn(
+                txn, "push_rules", {"user_name": user_id, "rule_id": rule_id}
+            )
+
+            self._insert_push_rules_update_txn(
+                txn, stream_id, event_stream_ordering, user_id, rule_id, op="DELETE"
+            )
+
+        with self._push_rules_stream_id_gen.get_next() as ids:
+            stream_id, event_stream_ordering = ids
+            yield self.runInteraction(
+                "delete_push_rule",
+                delete_push_rule_txn,
+                stream_id,
+                event_stream_ordering,
+            )
+
+    @defer.inlineCallbacks
+    def set_push_rule_enabled(self, user_id, rule_id, enabled):
+        with self._push_rules_stream_id_gen.get_next() as ids:
+            stream_id, event_stream_ordering = ids
+            yield self.runInteraction(
+                "_set_push_rule_enabled_txn",
+                self._set_push_rule_enabled_txn,
+                stream_id,
+                event_stream_ordering,
+                user_id,
+                rule_id,
+                enabled,
+            )
+
+    def _set_push_rule_enabled_txn(
+        self, txn, stream_id, event_stream_ordering, user_id, rule_id, enabled
+    ):
+        new_id = self._push_rules_enable_id_gen.get_next()
+        self._simple_upsert_txn(
+            txn,
+            "push_rules_enable",
+            {"user_name": user_id, "rule_id": rule_id},
+            {"enabled": 1 if enabled else 0},
+            {"id": new_id},
+        )
+
+        self._insert_push_rules_update_txn(
+            txn,
+            stream_id,
+            event_stream_ordering,
+            user_id,
+            rule_id,
+            op="ENABLE" if enabled else "DISABLE",
+        )
+
+    @defer.inlineCallbacks
+    def set_push_rule_actions(self, user_id, rule_id, actions, is_default_rule):
+        actions_json = json.dumps(actions)
+
+        def set_push_rule_actions_txn(txn, stream_id, event_stream_ordering):
+            if is_default_rule:
+                # Add a dummy rule to the rules table with the user specified
+                # actions.
+                priority_class = -1
+                priority = 1
+                self._upsert_push_rule_txn(
+                    txn,
+                    stream_id,
+                    event_stream_ordering,
+                    user_id,
+                    rule_id,
+                    priority_class,
+                    priority,
+                    "[]",
+                    actions_json,
+                    update_stream=False,
+                )
+            else:
+                self._simple_update_one_txn(
+                    txn,
+                    "push_rules",
+                    {"user_name": user_id, "rule_id": rule_id},
+                    {"actions": actions_json},
+                )
+
+            self._insert_push_rules_update_txn(
+                txn,
+                stream_id,
+                event_stream_ordering,
+                user_id,
+                rule_id,
+                op="ACTIONS",
+                data={"actions": actions_json},
+            )
+
+        with self._push_rules_stream_id_gen.get_next() as ids:
+            stream_id, event_stream_ordering = ids
+            yield self.runInteraction(
+                "set_push_rule_actions",
+                set_push_rule_actions_txn,
+                stream_id,
+                event_stream_ordering,
+            )
+
+    def _insert_push_rules_update_txn(
+        self, txn, stream_id, event_stream_ordering, user_id, rule_id, op, data=None
+    ):
+        values = {
+            "stream_id": stream_id,
+            "event_stream_ordering": event_stream_ordering,
+            "user_id": user_id,
+            "rule_id": rule_id,
+            "op": op,
+        }
+        if data is not None:
+            values.update(data)
+
+        self._simple_insert_txn(txn, "push_rules_stream", values=values)
+
+        txn.call_after(self.get_push_rules_for_user.invalidate, (user_id,))
+        txn.call_after(self.get_push_rules_enabled_for_user.invalidate, (user_id,))
+        txn.call_after(
+            self.push_rules_stream_cache.entity_has_changed, user_id, stream_id
+        )
+
+    def get_all_push_rule_updates(self, last_id, current_id, limit):
+        """Get all the push rules changes that have happend on the server"""
+        if last_id == current_id:
+            return defer.succeed([])
+
+        def get_all_push_rule_updates_txn(txn):
+            sql = (
+                "SELECT stream_id, event_stream_ordering, user_id, rule_id,"
+                " op, priority_class, priority, conditions, actions"
+                " FROM push_rules_stream"
+                " WHERE ? < stream_id AND stream_id <= ?"
+                " ORDER BY stream_id ASC LIMIT ?"
+            )
+            txn.execute(sql, (last_id, current_id, limit))
+            return txn.fetchall()
+
+        return self.runInteraction(
+            "get_all_push_rule_updates", get_all_push_rule_updates_txn
+        )
+
+    def get_push_rules_stream_token(self):
+        """Get the position of the push rules stream.
+        Returns a pair of a stream id for the push_rules stream and the
+        room stream ordering it corresponds to."""
+        return self._push_rules_stream_id_gen.get_current_token()
+
+    def get_max_push_rules_stream_id(self):
+        return self.get_push_rules_stream_token()[0]
diff --git a/synapse/storage/pusher.py b/synapse/storage/data_stores/main/pusher.py
index b12e80440a..f005c1ae0a 100644
--- a/synapse/storage/pusher.py
+++ b/synapse/storage/data_stores/main/pusher.py
@@ -22,10 +22,9 @@ from canonicaljson import encode_canonical_json, json
 
 from twisted.internet import defer
 
+from synapse.storage._base import SQLBaseStore
 from synapse.util.caches.descriptors import cachedInlineCallbacks, cachedList
 
-from ._base import SQLBaseStore
-
 logger = logging.getLogger(__name__)
 
 if six.PY2:
diff --git a/synapse/storage/receipts.py b/synapse/storage/data_stores/main/receipts.py
index 0c24430f28..0c24430f28 100644
--- a/synapse/storage/receipts.py
+++ b/synapse/storage/data_stores/main/receipts.py
diff --git a/synapse/storage/registration.py b/synapse/storage/data_stores/main/registration.py
index 6c5b29288a..6c5b29288a 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/data_stores/main/registration.py
diff --git a/synapse/storage/rejections.py b/synapse/storage/data_stores/main/rejections.py
index f4c1c2a457..7d5de0ea2e 100644
--- a/synapse/storage/rejections.py
+++ b/synapse/storage/data_stores/main/rejections.py
@@ -15,7 +15,7 @@
 
 import logging
 
-from ._base import SQLBaseStore
+from synapse.storage._base import SQLBaseStore
 
 logger = logging.getLogger(__name__)
 
diff --git a/synapse/storage/data_stores/main/relations.py b/synapse/storage/data_stores/main/relations.py
new file mode 100644
index 0000000000..858f65582b
--- /dev/null
+++ b/synapse/storage/data_stores/main/relations.py
@@ -0,0 +1,385 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+
+import attr
+
+from synapse.api.constants import RelationTypes
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.data_stores.main.stream import generate_pagination_where_clause
+from synapse.storage.relations import (
+    AggregationPaginationToken,
+    PaginationChunk,
+    RelationPaginationToken,
+)
+from synapse.util.caches.descriptors import cached, cachedInlineCallbacks
+
+logger = logging.getLogger(__name__)
+
+
+class RelationsWorkerStore(SQLBaseStore):
+    @cached(tree=True)
+    def get_relations_for_event(
+        self,
+        event_id,
+        relation_type=None,
+        event_type=None,
+        aggregation_key=None,
+        limit=5,
+        direction="b",
+        from_token=None,
+        to_token=None,
+    ):
+        """Get a list of relations for an event, ordered by topological ordering.
+
+        Args:
+            event_id (str): Fetch events that relate to this event ID.
+            relation_type (str|None): Only fetch events with this relation
+                type, if given.
+            event_type (str|None): Only fetch events with this event type, if
+                given.
+            aggregation_key (str|None): Only fetch events with this aggregation
+                key, if given.
+            limit (int): Only fetch the most recent `limit` events.
+            direction (str): Whether to fetch the most recent first (`"b"`) or
+                the oldest first (`"f"`).
+            from_token (RelationPaginationToken|None): Fetch rows from the given
+                token, or from the start if None.
+            to_token (RelationPaginationToken|None): Fetch rows up to the given
+                token, or up to the end if None.
+
+        Returns:
+            Deferred[PaginationChunk]: List of event IDs that match relations
+            requested. The rows are of the form `{"event_id": "..."}`.
+        """
+
+        where_clause = ["relates_to_id = ?"]
+        where_args = [event_id]
+
+        if relation_type is not None:
+            where_clause.append("relation_type = ?")
+            where_args.append(relation_type)
+
+        if event_type is not None:
+            where_clause.append("type = ?")
+            where_args.append(event_type)
+
+        if aggregation_key:
+            where_clause.append("aggregation_key = ?")
+            where_args.append(aggregation_key)
+
+        pagination_clause = generate_pagination_where_clause(
+            direction=direction,
+            column_names=("topological_ordering", "stream_ordering"),
+            from_token=attr.astuple(from_token) if from_token else None,
+            to_token=attr.astuple(to_token) if to_token else None,
+            engine=self.database_engine,
+        )
+
+        if pagination_clause:
+            where_clause.append(pagination_clause)
+
+        if direction == "b":
+            order = "DESC"
+        else:
+            order = "ASC"
+
+        sql = """
+            SELECT event_id, topological_ordering, stream_ordering
+            FROM event_relations
+            INNER JOIN events USING (event_id)
+            WHERE %s
+            ORDER BY topological_ordering %s, stream_ordering %s
+            LIMIT ?
+        """ % (
+            " AND ".join(where_clause),
+            order,
+            order,
+        )
+
+        def _get_recent_references_for_event_txn(txn):
+            txn.execute(sql, where_args + [limit + 1])
+
+            last_topo_id = None
+            last_stream_id = None
+            events = []
+            for row in txn:
+                events.append({"event_id": row[0]})
+                last_topo_id = row[1]
+                last_stream_id = row[2]
+
+            next_batch = None
+            if len(events) > limit and last_topo_id and last_stream_id:
+                next_batch = RelationPaginationToken(last_topo_id, last_stream_id)
+
+            return PaginationChunk(
+                chunk=list(events[:limit]), next_batch=next_batch, prev_batch=from_token
+            )
+
+        return self.runInteraction(
+            "get_recent_references_for_event", _get_recent_references_for_event_txn
+        )
+
+    @cached(tree=True)
+    def get_aggregation_groups_for_event(
+        self,
+        event_id,
+        event_type=None,
+        limit=5,
+        direction="b",
+        from_token=None,
+        to_token=None,
+    ):
+        """Get a list of annotations on the event, grouped by event type and
+        aggregation key, sorted by count.
+
+        This is used e.g. to get the what and how many reactions have happend
+        on an event.
+
+        Args:
+            event_id (str): Fetch events that relate to this event ID.
+            event_type (str|None): Only fetch events with this event type, if
+                given.
+            limit (int): Only fetch the `limit` groups.
+            direction (str): Whether to fetch the highest count first (`"b"`) or
+                the lowest count first (`"f"`).
+            from_token (AggregationPaginationToken|None): Fetch rows from the
+                given token, or from the start if None.
+            to_token (AggregationPaginationToken|None): Fetch rows up to the
+                given token, or up to the end if None.
+
+
+        Returns:
+            Deferred[PaginationChunk]: List of groups of annotations that
+            match. Each row is a dict with `type`, `key` and `count` fields.
+        """
+
+        where_clause = ["relates_to_id = ?", "relation_type = ?"]
+        where_args = [event_id, RelationTypes.ANNOTATION]
+
+        if event_type:
+            where_clause.append("type = ?")
+            where_args.append(event_type)
+
+        having_clause = generate_pagination_where_clause(
+            direction=direction,
+            column_names=("COUNT(*)", "MAX(stream_ordering)"),
+            from_token=attr.astuple(from_token) if from_token else None,
+            to_token=attr.astuple(to_token) if to_token else None,
+            engine=self.database_engine,
+        )
+
+        if direction == "b":
+            order = "DESC"
+        else:
+            order = "ASC"
+
+        if having_clause:
+            having_clause = "HAVING " + having_clause
+        else:
+            having_clause = ""
+
+        sql = """
+            SELECT type, aggregation_key, COUNT(DISTINCT sender), MAX(stream_ordering)
+            FROM event_relations
+            INNER JOIN events USING (event_id)
+            WHERE {where_clause}
+            GROUP BY relation_type, type, aggregation_key
+            {having_clause}
+            ORDER BY COUNT(*) {order}, MAX(stream_ordering) {order}
+            LIMIT ?
+        """.format(
+            where_clause=" AND ".join(where_clause),
+            order=order,
+            having_clause=having_clause,
+        )
+
+        def _get_aggregation_groups_for_event_txn(txn):
+            txn.execute(sql, where_args + [limit + 1])
+
+            next_batch = None
+            events = []
+            for row in txn:
+                events.append({"type": row[0], "key": row[1], "count": row[2]})
+                next_batch = AggregationPaginationToken(row[2], row[3])
+
+            if len(events) <= limit:
+                next_batch = None
+
+            return PaginationChunk(
+                chunk=list(events[:limit]), next_batch=next_batch, prev_batch=from_token
+            )
+
+        return self.runInteraction(
+            "get_aggregation_groups_for_event", _get_aggregation_groups_for_event_txn
+        )
+
+    @cachedInlineCallbacks()
+    def get_applicable_edit(self, event_id):
+        """Get the most recent edit (if any) that has happened for the given
+        event.
+
+        Correctly handles checking whether edits were allowed to happen.
+
+        Args:
+            event_id (str): The original event ID
+
+        Returns:
+            Deferred[EventBase|None]: Returns the most recent edit, if any.
+        """
+
+        # We only allow edits for `m.room.message` events that have the same sender
+        # and event type. We can't assert these things during regular event auth so
+        # we have to do the checks post hoc.
+
+        # Fetches latest edit that has the same type and sender as the
+        # original, and is an `m.room.message`.
+        sql = """
+            SELECT edit.event_id FROM events AS edit
+            INNER JOIN event_relations USING (event_id)
+            INNER JOIN events AS original ON
+                original.event_id = relates_to_id
+                AND edit.type = original.type
+                AND edit.sender = original.sender
+            WHERE
+                relates_to_id = ?
+                AND relation_type = ?
+                AND edit.type = 'm.room.message'
+            ORDER by edit.origin_server_ts DESC, edit.event_id DESC
+            LIMIT 1
+        """
+
+        def _get_applicable_edit_txn(txn):
+            txn.execute(sql, (event_id, RelationTypes.REPLACE))
+            row = txn.fetchone()
+            if row:
+                return row[0]
+
+        edit_id = yield self.runInteraction(
+            "get_applicable_edit", _get_applicable_edit_txn
+        )
+
+        if not edit_id:
+            return
+
+        edit_event = yield self.get_event(edit_id, allow_none=True)
+        return edit_event
+
+    def has_user_annotated_event(self, parent_id, event_type, aggregation_key, sender):
+        """Check if a user has already annotated an event with the same key
+        (e.g. already liked an event).
+
+        Args:
+            parent_id (str): The event being annotated
+            event_type (str): The event type of the annotation
+            aggregation_key (str): The aggregation key of the annotation
+            sender (str): The sender of the annotation
+
+        Returns:
+            Deferred[bool]
+        """
+
+        sql = """
+            SELECT 1 FROM event_relations
+            INNER JOIN events USING (event_id)
+            WHERE
+                relates_to_id = ?
+                AND relation_type = ?
+                AND type = ?
+                AND sender = ?
+                AND aggregation_key = ?
+            LIMIT 1;
+        """
+
+        def _get_if_user_has_annotated_event(txn):
+            txn.execute(
+                sql,
+                (
+                    parent_id,
+                    RelationTypes.ANNOTATION,
+                    event_type,
+                    sender,
+                    aggregation_key,
+                ),
+            )
+
+            return bool(txn.fetchone())
+
+        return self.runInteraction(
+            "get_if_user_has_annotated_event", _get_if_user_has_annotated_event
+        )
+
+
+class RelationsStore(RelationsWorkerStore):
+    def _handle_event_relations(self, txn, event):
+        """Handles inserting relation data during peristence of events
+
+        Args:
+            txn
+            event (EventBase)
+        """
+        relation = event.content.get("m.relates_to")
+        if not relation:
+            # No relations
+            return
+
+        rel_type = relation.get("rel_type")
+        if rel_type not in (
+            RelationTypes.ANNOTATION,
+            RelationTypes.REFERENCE,
+            RelationTypes.REPLACE,
+        ):
+            # Unknown relation type
+            return
+
+        parent_id = relation.get("event_id")
+        if not parent_id:
+            # Invalid relation
+            return
+
+        aggregation_key = relation.get("key")
+
+        self._simple_insert_txn(
+            txn,
+            table="event_relations",
+            values={
+                "event_id": event.event_id,
+                "relates_to_id": parent_id,
+                "relation_type": rel_type,
+                "aggregation_key": aggregation_key,
+            },
+        )
+
+        txn.call_after(self.get_relations_for_event.invalidate_many, (parent_id,))
+        txn.call_after(
+            self.get_aggregation_groups_for_event.invalidate_many, (parent_id,)
+        )
+
+        if rel_type == RelationTypes.REPLACE:
+            txn.call_after(self.get_applicable_edit.invalidate, (parent_id,))
+
+    def _handle_redaction(self, txn, redacted_event_id):
+        """Handles receiving a redaction and checking whether we need to remove
+        any redacted relations from the database.
+
+        Args:
+            txn
+            redacted_event_id (str): The event that was redacted.
+        """
+
+        self._simple_delete_txn(
+            txn, table="event_relations", keyvalues={"event_id": redacted_event_id}
+        )
diff --git a/synapse/storage/room.py b/synapse/storage/data_stores/main/room.py
index 43cc56fa6f..4428e5c55d 100644
--- a/synapse/storage/room.py
+++ b/synapse/storage/data_stores/main/room.py
@@ -25,7 +25,7 @@ from twisted.internet import defer
 
 from synapse.api.errors import StoreError
 from synapse.storage._base import SQLBaseStore
-from synapse.storage.search import SearchStore
+from synapse.storage.data_stores.main.search import SearchStore
 from synapse.types import ThirdPartyInstanceID
 from synapse.util.caches.descriptors import cached, cachedInlineCallbacks
 
diff --git a/synapse/storage/data_stores/main/roommember.py b/synapse/storage/data_stores/main/roommember.py
new file mode 100644
index 0000000000..e47ab604dd
--- /dev/null
+++ b/synapse/storage/data_stores/main/roommember.py
@@ -0,0 +1,1145 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+
+from six import iteritems, itervalues
+
+from canonicaljson import json
+
+from twisted.internet import defer
+
+from synapse.api.constants import EventTypes, Membership
+from synapse.metrics import LaterGauge
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.storage._base import LoggingTransaction, make_in_list_sql_clause
+from synapse.storage.background_updates import BackgroundUpdateStore
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
+from synapse.storage.engines import Sqlite3Engine
+from synapse.storage.roommember import (
+    GetRoomsForUserWithStreamOrdering,
+    MemberSummary,
+    ProfileInfo,
+    RoomsForUser,
+)
+from synapse.types import get_domain_from_id
+from synapse.util.async_helpers import Linearizer
+from synapse.util.caches import intern_string
+from synapse.util.caches.descriptors import cached, cachedInlineCallbacks, cachedList
+from synapse.util.metrics import Measure
+from synapse.util.stringutils import to_ascii
+
+logger = logging.getLogger(__name__)
+
+
+_MEMBERSHIP_PROFILE_UPDATE_NAME = "room_membership_profile_update"
+_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME = "current_state_events_membership"
+
+
+class RoomMemberWorkerStore(EventsWorkerStore):
+    def __init__(self, db_conn, hs):
+        super(RoomMemberWorkerStore, self).__init__(db_conn, hs)
+
+        # Is the current_state_events.membership up to date? Or is the
+        # background update still running?
+        self._current_state_events_membership_up_to_date = False
+
+        txn = LoggingTransaction(
+            db_conn.cursor(),
+            name="_check_safe_current_state_events_membership_updated",
+            database_engine=self.database_engine,
+        )
+        self._check_safe_current_state_events_membership_updated_txn(txn)
+        txn.close()
+
+        if self.hs.config.metrics_flags.known_servers:
+            self._known_servers_count = 1
+            self.hs.get_clock().looping_call(
+                run_as_background_process,
+                60 * 1000,
+                "_count_known_servers",
+                self._count_known_servers,
+            )
+            self.hs.get_clock().call_later(
+                1000,
+                run_as_background_process,
+                "_count_known_servers",
+                self._count_known_servers,
+            )
+            LaterGauge(
+                "synapse_federation_known_servers",
+                "",
+                [],
+                lambda: self._known_servers_count,
+            )
+
+    @defer.inlineCallbacks
+    def _count_known_servers(self):
+        """
+        Count the servers that this server knows about.
+
+        The statistic is stored on the class for the
+        `synapse_federation_known_servers` LaterGauge to collect.
+        """
+
+        def _transact(txn):
+            if isinstance(self.database_engine, Sqlite3Engine):
+                query = """
+                    SELECT COUNT(DISTINCT substr(out.user_id, pos+1))
+                    FROM (
+                        SELECT rm.user_id as user_id, instr(rm.user_id, ':')
+                            AS pos FROM room_memberships as rm
+                        INNER JOIN current_state_events as c ON rm.event_id = c.event_id
+                        WHERE c.type = 'm.room.member'
+                    ) as out
+                """
+            else:
+                query = """
+                    SELECT COUNT(DISTINCT split_part(state_key, ':', 2))
+                    FROM current_state_events
+                    WHERE type = 'm.room.member' AND membership = 'join';
+                """
+            txn.execute(query)
+            return list(txn)[0][0]
+
+        count = yield self.runInteraction("get_known_servers", _transact)
+
+        # We always know about ourselves, even if we have nothing in
+        # room_memberships (for example, the server is new).
+        self._known_servers_count = max([count, 1])
+        return self._known_servers_count
+
+    def _check_safe_current_state_events_membership_updated_txn(self, txn):
+        """Checks if it is safe to assume the new current_state_events
+        membership column is up to date
+        """
+
+        pending_update = self._simple_select_one_txn(
+            txn,
+            table="background_updates",
+            keyvalues={"update_name": _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME},
+            retcols=["update_name"],
+            allow_none=True,
+        )
+
+        self._current_state_events_membership_up_to_date = not pending_update
+
+        # If the update is still running, reschedule to run.
+        if pending_update:
+            self._clock.call_later(
+                15.0,
+                run_as_background_process,
+                "_check_safe_current_state_events_membership_updated",
+                self.runInteraction,
+                "_check_safe_current_state_events_membership_updated",
+                self._check_safe_current_state_events_membership_updated_txn,
+            )
+
+    @cachedInlineCallbacks(max_entries=100000, iterable=True, cache_context=True)
+    def get_hosts_in_room(self, room_id, cache_context):
+        """Returns the set of all hosts currently in the room
+        """
+        user_ids = yield self.get_users_in_room(
+            room_id, on_invalidate=cache_context.invalidate
+        )
+        hosts = frozenset(get_domain_from_id(user_id) for user_id in user_ids)
+        return hosts
+
+    @cached(max_entries=100000, iterable=True)
+    def get_users_in_room(self, room_id):
+        return self.runInteraction(
+            "get_users_in_room", self.get_users_in_room_txn, room_id
+        )
+
+    def get_users_in_room_txn(self, txn, room_id):
+        # If we can assume current_state_events.membership is up to date
+        # then we can avoid a join, which is a Very Good Thing given how
+        # frequently this function gets called.
+        if self._current_state_events_membership_up_to_date:
+            sql = """
+                SELECT state_key FROM current_state_events
+                WHERE type = 'm.room.member' AND room_id = ? AND membership = ?
+            """
+        else:
+            sql = """
+                SELECT state_key FROM room_memberships as m
+                INNER JOIN current_state_events as c
+                ON m.event_id = c.event_id
+                AND m.room_id = c.room_id
+                AND m.user_id = c.state_key
+                WHERE c.type = 'm.room.member' AND c.room_id = ? AND m.membership = ?
+            """
+
+        txn.execute(sql, (room_id, Membership.JOIN))
+        return [to_ascii(r[0]) for r in txn]
+
+    @cached(max_entries=100000)
+    def get_room_summary(self, room_id):
+        """ Get the details of a room roughly suitable for use by the room
+        summary extension to /sync. Useful when lazy loading room members.
+        Args:
+            room_id (str): The room ID to query
+        Returns:
+            Deferred[dict[str, MemberSummary]:
+                dict of membership states, pointing to a MemberSummary named tuple.
+        """
+
+        def _get_room_summary_txn(txn):
+            # first get counts.
+            # We do this all in one transaction to keep the cache small.
+            # FIXME: get rid of this when we have room_stats
+
+            # If we can assume current_state_events.membership is up to date
+            # then we can avoid a join, which is a Very Good Thing given how
+            # frequently this function gets called.
+            if self._current_state_events_membership_up_to_date:
+                # Note, rejected events will have a null membership field, so
+                # we we manually filter them out.
+                sql = """
+                    SELECT count(*), membership FROM current_state_events
+                    WHERE type = 'm.room.member' AND room_id = ?
+                        AND membership IS NOT NULL
+                    GROUP BY membership
+                """
+            else:
+                sql = """
+                    SELECT count(*), m.membership FROM room_memberships as m
+                    INNER JOIN current_state_events as c
+                    ON m.event_id = c.event_id
+                    AND m.room_id = c.room_id
+                    AND m.user_id = c.state_key
+                    WHERE c.type = 'm.room.member' AND c.room_id = ?
+                    GROUP BY m.membership
+                """
+
+            txn.execute(sql, (room_id,))
+            res = {}
+            for count, membership in txn:
+                summary = res.setdefault(to_ascii(membership), MemberSummary([], count))
+
+            # we order by membership and then fairly arbitrarily by event_id so
+            # heroes are consistent
+            if self._current_state_events_membership_up_to_date:
+                # Note, rejected events will have a null membership field, so
+                # we we manually filter them out.
+                sql = """
+                    SELECT state_key, membership, event_id
+                    FROM current_state_events
+                    WHERE type = 'm.room.member' AND room_id = ?
+                        AND membership IS NOT NULL
+                    ORDER BY
+                        CASE membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
+                        event_id ASC
+                    LIMIT ?
+                """
+            else:
+                sql = """
+                    SELECT c.state_key, m.membership, c.event_id
+                    FROM room_memberships as m
+                    INNER JOIN current_state_events as c USING (room_id, event_id)
+                    WHERE c.type = 'm.room.member' AND c.room_id = ?
+                    ORDER BY
+                        CASE m.membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
+                        c.event_id ASC
+                    LIMIT ?
+                """
+
+            # 6 is 5 (number of heroes) plus 1, in case one of them is the calling user.
+            txn.execute(sql, (room_id, Membership.JOIN, Membership.INVITE, 6))
+            for user_id, membership, event_id in txn:
+                summary = res[to_ascii(membership)]
+                # we will always have a summary for this membership type at this
+                # point given the summary currently contains the counts.
+                members = summary.members
+                members.append((to_ascii(user_id), to_ascii(event_id)))
+
+            return res
+
+        return self.runInteraction("get_room_summary", _get_room_summary_txn)
+
+    def _get_user_counts_in_room_txn(self, txn, room_id):
+        """
+        Get the user count in a room by membership.
+
+        Args:
+            room_id (str)
+            membership (Membership)
+
+        Returns:
+            Deferred[int]
+        """
+        sql = """
+        SELECT m.membership, count(*) FROM room_memberships as m
+            INNER JOIN current_state_events as c USING(event_id)
+            WHERE c.type = 'm.room.member' AND c.room_id = ?
+            GROUP BY m.membership
+        """
+
+        txn.execute(sql, (room_id,))
+        return {row[0]: row[1] for row in txn}
+
+    @cached()
+    def get_invited_rooms_for_user(self, user_id):
+        """ Get all the rooms the user is invited to
+        Args:
+            user_id (str): The user ID.
+        Returns:
+            A deferred list of RoomsForUser.
+        """
+
+        return self.get_rooms_for_user_where_membership_is(user_id, [Membership.INVITE])
+
+    @defer.inlineCallbacks
+    def get_invite_for_user_in_room(self, user_id, room_id):
+        """Gets the invite for the given user and room
+
+        Args:
+            user_id (str)
+            room_id (str)
+
+        Returns:
+            Deferred: Resolves to either a RoomsForUser or None if no invite was
+                found.
+        """
+        invites = yield self.get_invited_rooms_for_user(user_id)
+        for invite in invites:
+            if invite.room_id == room_id:
+                return invite
+        return None
+
+    @defer.inlineCallbacks
+    def get_rooms_for_user_where_membership_is(self, user_id, membership_list):
+        """ Get all the rooms for this user where the membership for this user
+        matches one in the membership list.
+
+        Filters out forgotten rooms.
+
+        Args:
+            user_id (str): The user ID.
+            membership_list (list): A list of synapse.api.constants.Membership
+            values which the user must be in.
+
+        Returns:
+            Deferred[list[RoomsForUser]]
+        """
+        if not membership_list:
+            return defer.succeed(None)
+
+        rooms = yield self.runInteraction(
+            "get_rooms_for_user_where_membership_is",
+            self._get_rooms_for_user_where_membership_is_txn,
+            user_id,
+            membership_list,
+        )
+
+        # Now we filter out forgotten rooms
+        forgotten_rooms = yield self.get_forgotten_rooms_for_user(user_id)
+        return [room for room in rooms if room.room_id not in forgotten_rooms]
+
+    def _get_rooms_for_user_where_membership_is_txn(
+        self, txn, user_id, membership_list
+    ):
+
+        do_invite = Membership.INVITE in membership_list
+        membership_list = [m for m in membership_list if m != Membership.INVITE]
+
+        results = []
+        if membership_list:
+            if self._current_state_events_membership_up_to_date:
+                clause, args = make_in_list_sql_clause(
+                    self.database_engine, "c.membership", membership_list
+                )
+                sql = """
+                    SELECT room_id, e.sender, c.membership, event_id, e.stream_ordering
+                    FROM current_state_events AS c
+                    INNER JOIN events AS e USING (room_id, event_id)
+                    WHERE
+                        c.type = 'm.room.member'
+                        AND state_key = ?
+                        AND %s
+                """ % (
+                    clause,
+                )
+            else:
+                clause, args = make_in_list_sql_clause(
+                    self.database_engine, "m.membership", membership_list
+                )
+                sql = """
+                    SELECT room_id, e.sender, m.membership, event_id, e.stream_ordering
+                    FROM current_state_events AS c
+                    INNER JOIN room_memberships AS m USING (room_id, event_id)
+                    INNER JOIN events AS e USING (room_id, event_id)
+                    WHERE
+                        c.type = 'm.room.member'
+                        AND state_key = ?
+                        AND %s
+                """ % (
+                    clause,
+                )
+
+            txn.execute(sql, (user_id, *args))
+            results = [RoomsForUser(**r) for r in self.cursor_to_dict(txn)]
+
+        if do_invite:
+            sql = (
+                "SELECT i.room_id, inviter, i.event_id, e.stream_ordering"
+                " FROM local_invites as i"
+                " INNER JOIN events as e USING (event_id)"
+                " WHERE invitee = ? AND locally_rejected is NULL"
+                " AND replaced_by is NULL"
+            )
+
+            txn.execute(sql, (user_id,))
+            results.extend(
+                RoomsForUser(
+                    room_id=r["room_id"],
+                    sender=r["inviter"],
+                    event_id=r["event_id"],
+                    stream_ordering=r["stream_ordering"],
+                    membership=Membership.INVITE,
+                )
+                for r in self.cursor_to_dict(txn)
+            )
+
+        return results
+
+    @cachedInlineCallbacks(max_entries=500000, iterable=True)
+    def get_rooms_for_user_with_stream_ordering(self, user_id):
+        """Returns a set of room_ids the user is currently joined to
+
+        Args:
+            user_id (str)
+
+        Returns:
+            Deferred[frozenset[GetRoomsForUserWithStreamOrdering]]: Returns
+            the rooms the user is in currently, along with the stream ordering
+            of the most recent join for that user and room.
+        """
+        rooms = yield self.get_rooms_for_user_where_membership_is(
+            user_id, membership_list=[Membership.JOIN]
+        )
+        return frozenset(
+            GetRoomsForUserWithStreamOrdering(r.room_id, r.stream_ordering)
+            for r in rooms
+        )
+
+    @defer.inlineCallbacks
+    def get_rooms_for_user(self, user_id, on_invalidate=None):
+        """Returns a set of room_ids the user is currently joined to
+        """
+        rooms = yield self.get_rooms_for_user_with_stream_ordering(
+            user_id, on_invalidate=on_invalidate
+        )
+        return frozenset(r.room_id for r in rooms)
+
+    @cachedInlineCallbacks(max_entries=500000, cache_context=True, iterable=True)
+    def get_users_who_share_room_with_user(self, user_id, cache_context):
+        """Returns the set of users who share a room with `user_id`
+        """
+        room_ids = yield self.get_rooms_for_user(
+            user_id, on_invalidate=cache_context.invalidate
+        )
+
+        user_who_share_room = set()
+        for room_id in room_ids:
+            user_ids = yield self.get_users_in_room(
+                room_id, on_invalidate=cache_context.invalidate
+            )
+            user_who_share_room.update(user_ids)
+
+        return user_who_share_room
+
+    @defer.inlineCallbacks
+    def get_joined_users_from_context(self, event, context):
+        state_group = context.state_group
+        if not state_group:
+            # If state_group is None it means it has yet to be assigned a
+            # state group, i.e. we need to make sure that calls with a state_group
+            # of None don't hit previous cached calls with a None state_group.
+            # To do this we set the state_group to a new object as object() != object()
+            state_group = object()
+
+        current_state_ids = yield context.get_current_state_ids(self)
+        result = yield self._get_joined_users_from_context(
+            event.room_id, state_group, current_state_ids, event=event, context=context
+        )
+        return result
+
+    @defer.inlineCallbacks
+    def get_joined_users_from_state(self, room_id, state_entry):
+        state_group = state_entry.state_group
+        if not state_group:
+            # If state_group is None it means it has yet to be assigned a
+            # state group, i.e. we need to make sure that calls with a state_group
+            # of None don't hit previous cached calls with a None state_group.
+            # To do this we set the state_group to a new object as object() != object()
+            state_group = object()
+
+        with Measure(self._clock, "get_joined_users_from_state"):
+            return (
+                yield self._get_joined_users_from_context(
+                    room_id, state_group, state_entry.state, context=state_entry
+                )
+            )
+
+    @cachedInlineCallbacks(
+        num_args=2, cache_context=True, iterable=True, max_entries=100000
+    )
+    def _get_joined_users_from_context(
+        self,
+        room_id,
+        state_group,
+        current_state_ids,
+        cache_context,
+        event=None,
+        context=None,
+    ):
+        # We don't use `state_group`, it's there so that we can cache based
+        # on it. However, it's important that it's never None, since two current_states
+        # with a state_group of None are likely to be different.
+        # See bulk_get_push_rules_for_room for how we work around this.
+        assert state_group is not None
+
+        users_in_room = {}
+        member_event_ids = [
+            e_id
+            for key, e_id in iteritems(current_state_ids)
+            if key[0] == EventTypes.Member
+        ]
+
+        if context is not None:
+            # If we have a context with a delta from a previous state group,
+            # check if we also have the result from the previous group in cache.
+            # If we do then we can reuse that result and simply update it with
+            # any membership changes in `delta_ids`
+            if context.prev_group and context.delta_ids:
+                prev_res = self._get_joined_users_from_context.cache.get(
+                    (room_id, context.prev_group), None
+                )
+                if prev_res and isinstance(prev_res, dict):
+                    users_in_room = dict(prev_res)
+                    member_event_ids = [
+                        e_id
+                        for key, e_id in iteritems(context.delta_ids)
+                        if key[0] == EventTypes.Member
+                    ]
+                    for etype, state_key in context.delta_ids:
+                        users_in_room.pop(state_key, None)
+
+        # We check if we have any of the member event ids in the event cache
+        # before we ask the DB
+
+        # We don't update the event cache hit ratio as it completely throws off
+        # the hit ratio counts. After all, we don't populate the cache if we
+        # miss it here
+        event_map = self._get_events_from_cache(
+            member_event_ids, allow_rejected=False, update_metrics=False
+        )
+
+        missing_member_event_ids = []
+        for event_id in member_event_ids:
+            ev_entry = event_map.get(event_id)
+            if ev_entry:
+                if ev_entry.event.membership == Membership.JOIN:
+                    users_in_room[to_ascii(ev_entry.event.state_key)] = ProfileInfo(
+                        display_name=to_ascii(
+                            ev_entry.event.content.get("displayname", None)
+                        ),
+                        avatar_url=to_ascii(
+                            ev_entry.event.content.get("avatar_url", None)
+                        ),
+                    )
+            else:
+                missing_member_event_ids.append(event_id)
+
+        if missing_member_event_ids:
+            event_to_memberships = yield self._get_joined_profiles_from_event_ids(
+                missing_member_event_ids
+            )
+            users_in_room.update((row for row in event_to_memberships.values() if row))
+
+        if event is not None and event.type == EventTypes.Member:
+            if event.membership == Membership.JOIN:
+                if event.event_id in member_event_ids:
+                    users_in_room[to_ascii(event.state_key)] = ProfileInfo(
+                        display_name=to_ascii(event.content.get("displayname", None)),
+                        avatar_url=to_ascii(event.content.get("avatar_url", None)),
+                    )
+
+        return users_in_room
+
+    @cached(max_entries=10000)
+    def _get_joined_profile_from_event_id(self, event_id):
+        raise NotImplementedError()
+
+    @cachedList(
+        cached_method_name="_get_joined_profile_from_event_id",
+        list_name="event_ids",
+        inlineCallbacks=True,
+    )
+    def _get_joined_profiles_from_event_ids(self, event_ids):
+        """For given set of member event_ids check if they point to a join
+        event and if so return the associated user and profile info.
+
+        Args:
+            event_ids (Iterable[str]): The member event IDs to lookup
+
+        Returns:
+            Deferred[dict[str, Tuple[str, ProfileInfo]|None]]: Map from event ID
+            to `user_id` and ProfileInfo (or None if not join event).
+        """
+
+        rows = yield self._simple_select_many_batch(
+            table="room_memberships",
+            column="event_id",
+            iterable=event_ids,
+            retcols=("user_id", "display_name", "avatar_url", "event_id"),
+            keyvalues={"membership": Membership.JOIN},
+            batch_size=500,
+            desc="_get_membership_from_event_ids",
+        )
+
+        return {
+            row["event_id"]: (
+                row["user_id"],
+                ProfileInfo(
+                    avatar_url=row["avatar_url"], display_name=row["display_name"]
+                ),
+            )
+            for row in rows
+        }
+
+    @cachedInlineCallbacks(max_entries=10000)
+    def is_host_joined(self, room_id, host):
+        if "%" in host or "_" in host:
+            raise Exception("Invalid host name")
+
+        sql = """
+            SELECT state_key FROM current_state_events AS c
+            INNER JOIN room_memberships AS m USING (event_id)
+            WHERE m.membership = 'join'
+                AND type = 'm.room.member'
+                AND c.room_id = ?
+                AND state_key LIKE ?
+            LIMIT 1
+        """
+
+        # We do need to be careful to ensure that host doesn't have any wild cards
+        # in it, but we checked above for known ones and we'll check below that
+        # the returned user actually has the correct domain.
+        like_clause = "%:" + host
+
+        rows = yield self._execute("is_host_joined", None, sql, room_id, like_clause)
+
+        if not rows:
+            return False
+
+        user_id = rows[0][0]
+        if get_domain_from_id(user_id) != host:
+            # This can only happen if the host name has something funky in it
+            raise Exception("Invalid host name")
+
+        return True
+
+    @cachedInlineCallbacks()
+    def was_host_joined(self, room_id, host):
+        """Check whether the server is or ever was in the room.
+
+        Args:
+            room_id (str)
+            host (str)
+
+        Returns:
+            Deferred: Resolves to True if the host is/was in the room, otherwise
+            False.
+        """
+        if "%" in host or "_" in host:
+            raise Exception("Invalid host name")
+
+        sql = """
+            SELECT user_id FROM room_memberships
+            WHERE room_id = ?
+                AND user_id LIKE ?
+                AND membership = 'join'
+            LIMIT 1
+        """
+
+        # We do need to be careful to ensure that host doesn't have any wild cards
+        # in it, but we checked above for known ones and we'll check below that
+        # the returned user actually has the correct domain.
+        like_clause = "%:" + host
+
+        rows = yield self._execute("was_host_joined", None, sql, room_id, like_clause)
+
+        if not rows:
+            return False
+
+        user_id = rows[0][0]
+        if get_domain_from_id(user_id) != host:
+            # This can only happen if the host name has something funky in it
+            raise Exception("Invalid host name")
+
+        return True
+
+    @defer.inlineCallbacks
+    def get_joined_hosts(self, room_id, state_entry):
+        state_group = state_entry.state_group
+        if not state_group:
+            # If state_group is None it means it has yet to be assigned a
+            # state group, i.e. we need to make sure that calls with a state_group
+            # of None don't hit previous cached calls with a None state_group.
+            # To do this we set the state_group to a new object as object() != object()
+            state_group = object()
+
+        with Measure(self._clock, "get_joined_hosts"):
+            return (
+                yield self._get_joined_hosts(
+                    room_id, state_group, state_entry.state, state_entry=state_entry
+                )
+            )
+
+    @cachedInlineCallbacks(num_args=2, max_entries=10000, iterable=True)
+    # @defer.inlineCallbacks
+    def _get_joined_hosts(self, room_id, state_group, current_state_ids, state_entry):
+        # We don't use `state_group`, its there so that we can cache based
+        # on it. However, its important that its never None, since two current_state's
+        # with a state_group of None are likely to be different.
+        # See bulk_get_push_rules_for_room for how we work around this.
+        assert state_group is not None
+
+        cache = self._get_joined_hosts_cache(room_id)
+        joined_hosts = yield cache.get_destinations(state_entry)
+
+        return joined_hosts
+
+    @cached(max_entries=10000)
+    def _get_joined_hosts_cache(self, room_id):
+        return _JoinedHostsCache(self, room_id)
+
+    @cachedInlineCallbacks(num_args=2)
+    def did_forget(self, user_id, room_id):
+        """Returns whether user_id has elected to discard history for room_id.
+
+        Returns False if they have since re-joined."""
+
+        def f(txn):
+            sql = (
+                "SELECT"
+                "  COUNT(*)"
+                " FROM"
+                "  room_memberships"
+                " WHERE"
+                "  user_id = ?"
+                " AND"
+                "  room_id = ?"
+                " AND"
+                "  forgotten = 0"
+            )
+            txn.execute(sql, (user_id, room_id))
+            rows = txn.fetchall()
+            return rows[0][0]
+
+        count = yield self.runInteraction("did_forget_membership", f)
+        return count == 0
+
+    @cached()
+    def get_forgotten_rooms_for_user(self, user_id):
+        """Gets all rooms the user has forgotten.
+
+        Args:
+            user_id (str)
+
+        Returns:
+            Deferred[set[str]]
+        """
+
+        def _get_forgotten_rooms_for_user_txn(txn):
+            # This is a slightly convoluted query that first looks up all rooms
+            # that the user has forgotten in the past, then rechecks that list
+            # to see if any have subsequently been updated. This is done so that
+            # we can use a partial index on `forgotten = 1` on the assumption
+            # that few users will actually forget many rooms.
+            #
+            # Note that a room is considered "forgotten" if *all* membership
+            # events for that user and room have the forgotten field set (as
+            # when a user forgets a room we update all rows for that user and
+            # room, not just the current one).
+            sql = """
+                SELECT room_id, (
+                    SELECT count(*) FROM room_memberships
+                    WHERE room_id = m.room_id AND user_id = m.user_id AND forgotten = 0
+                ) AS count
+                FROM room_memberships AS m
+                WHERE user_id = ? AND forgotten = 1
+                GROUP BY room_id, user_id;
+            """
+            txn.execute(sql, (user_id,))
+            return set(row[0] for row in txn if row[1] == 0)
+
+        return self.runInteraction(
+            "get_forgotten_rooms_for_user", _get_forgotten_rooms_for_user_txn
+        )
+
+    @defer.inlineCallbacks
+    def get_rooms_user_has_been_in(self, user_id):
+        """Get all rooms that the user has ever been in.
+
+        Args:
+            user_id (str)
+
+        Returns:
+            Deferred[set[str]]: Set of room IDs.
+        """
+
+        room_ids = yield self._simple_select_onecol(
+            table="room_memberships",
+            keyvalues={"membership": Membership.JOIN, "user_id": user_id},
+            retcol="room_id",
+            desc="get_rooms_user_has_been_in",
+        )
+
+        return set(room_ids)
+
+
+class RoomMemberBackgroundUpdateStore(BackgroundUpdateStore):
+    def __init__(self, db_conn, hs):
+        super(RoomMemberBackgroundUpdateStore, self).__init__(db_conn, hs)
+        self.register_background_update_handler(
+            _MEMBERSHIP_PROFILE_UPDATE_NAME, self._background_add_membership_profile
+        )
+        self.register_background_update_handler(
+            _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME,
+            self._background_current_state_membership,
+        )
+        self.register_background_index_update(
+            "room_membership_forgotten_idx",
+            index_name="room_memberships_user_room_forgotten",
+            table="room_memberships",
+            columns=["user_id", "room_id"],
+            where_clause="forgotten = 1",
+        )
+
+    @defer.inlineCallbacks
+    def _background_add_membership_profile(self, progress, batch_size):
+        target_min_stream_id = progress.get(
+            "target_min_stream_id_inclusive", self._min_stream_order_on_start
+        )
+        max_stream_id = progress.get(
+            "max_stream_id_exclusive", self._stream_order_on_start + 1
+        )
+
+        INSERT_CLUMP_SIZE = 1000
+
+        def add_membership_profile_txn(txn):
+            sql = """
+                SELECT stream_ordering, event_id, events.room_id, event_json.json
+                FROM events
+                INNER JOIN event_json USING (event_id)
+                INNER JOIN room_memberships USING (event_id)
+                WHERE ? <= stream_ordering AND stream_ordering < ?
+                AND type = 'm.room.member'
+                ORDER BY stream_ordering DESC
+                LIMIT ?
+            """
+
+            txn.execute(sql, (target_min_stream_id, max_stream_id, batch_size))
+
+            rows = self.cursor_to_dict(txn)
+            if not rows:
+                return 0
+
+            min_stream_id = rows[-1]["stream_ordering"]
+
+            to_update = []
+            for row in rows:
+                event_id = row["event_id"]
+                room_id = row["room_id"]
+                try:
+                    event_json = json.loads(row["json"])
+                    content = event_json["content"]
+                except Exception:
+                    continue
+
+                display_name = content.get("displayname", None)
+                avatar_url = content.get("avatar_url", None)
+
+                if display_name or avatar_url:
+                    to_update.append((display_name, avatar_url, event_id, room_id))
+
+            to_update_sql = """
+                UPDATE room_memberships SET display_name = ?, avatar_url = ?
+                WHERE event_id = ? AND room_id = ?
+            """
+            for index in range(0, len(to_update), INSERT_CLUMP_SIZE):
+                clump = to_update[index : index + INSERT_CLUMP_SIZE]
+                txn.executemany(to_update_sql, clump)
+
+            progress = {
+                "target_min_stream_id_inclusive": target_min_stream_id,
+                "max_stream_id_exclusive": min_stream_id,
+            }
+
+            self._background_update_progress_txn(
+                txn, _MEMBERSHIP_PROFILE_UPDATE_NAME, progress
+            )
+
+            return len(rows)
+
+        result = yield self.runInteraction(
+            _MEMBERSHIP_PROFILE_UPDATE_NAME, add_membership_profile_txn
+        )
+
+        if not result:
+            yield self._end_background_update(_MEMBERSHIP_PROFILE_UPDATE_NAME)
+
+        return result
+
+    @defer.inlineCallbacks
+    def _background_current_state_membership(self, progress, batch_size):
+        """Update the new membership column on current_state_events.
+
+        This works by iterating over all rooms in alphebetical order.
+        """
+
+        def _background_current_state_membership_txn(txn, last_processed_room):
+            processed = 0
+            while processed < batch_size:
+                txn.execute(
+                    """
+                        SELECT MIN(room_id) FROM current_state_events WHERE room_id > ?
+                    """,
+                    (last_processed_room,),
+                )
+                row = txn.fetchone()
+                if not row or not row[0]:
+                    return processed, True
+
+                next_room, = row
+
+                sql = """
+                    UPDATE current_state_events
+                    SET membership = (
+                        SELECT membership FROM room_memberships
+                        WHERE event_id = current_state_events.event_id
+                    )
+                    WHERE room_id = ?
+                """
+                txn.execute(sql, (next_room,))
+                processed += txn.rowcount
+
+                last_processed_room = next_room
+
+            self._background_update_progress_txn(
+                txn,
+                _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME,
+                {"last_processed_room": last_processed_room},
+            )
+
+            return processed, False
+
+        # If we haven't got a last processed room then just use the empty
+        # string, which will compare before all room IDs correctly.
+        last_processed_room = progress.get("last_processed_room", "")
+
+        row_count, finished = yield self.runInteraction(
+            "_background_current_state_membership_update",
+            _background_current_state_membership_txn,
+            last_processed_room,
+        )
+
+        if finished:
+            yield self._end_background_update(_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME)
+
+        return row_count
+
+
+class RoomMemberStore(RoomMemberWorkerStore, RoomMemberBackgroundUpdateStore):
+    def __init__(self, db_conn, hs):
+        super(RoomMemberStore, self).__init__(db_conn, hs)
+
+    def _store_room_members_txn(self, txn, events, backfilled):
+        """Store a room member in the database.
+        """
+        self._simple_insert_many_txn(
+            txn,
+            table="room_memberships",
+            values=[
+                {
+                    "event_id": event.event_id,
+                    "user_id": event.state_key,
+                    "sender": event.user_id,
+                    "room_id": event.room_id,
+                    "membership": event.membership,
+                    "display_name": event.content.get("displayname", None),
+                    "avatar_url": event.content.get("avatar_url", None),
+                }
+                for event in events
+            ],
+        )
+
+        for event in events:
+            txn.call_after(
+                self._membership_stream_cache.entity_has_changed,
+                event.state_key,
+                event.internal_metadata.stream_ordering,
+            )
+            txn.call_after(
+                self.get_invited_rooms_for_user.invalidate, (event.state_key,)
+            )
+
+            # We update the local_invites table only if the event is "current",
+            # i.e., its something that has just happened. If the event is an
+            # outlier it is only current if its an "out of band membership",
+            # like a remote invite or a rejection of a remote invite.
+            is_new_state = not backfilled and (
+                not event.internal_metadata.is_outlier()
+                or event.internal_metadata.is_out_of_band_membership()
+            )
+            is_mine = self.hs.is_mine_id(event.state_key)
+            if is_new_state and is_mine:
+                if event.membership == Membership.INVITE:
+                    self._simple_insert_txn(
+                        txn,
+                        table="local_invites",
+                        values={
+                            "event_id": event.event_id,
+                            "invitee": event.state_key,
+                            "inviter": event.sender,
+                            "room_id": event.room_id,
+                            "stream_id": event.internal_metadata.stream_ordering,
+                        },
+                    )
+                else:
+                    sql = (
+                        "UPDATE local_invites SET stream_id = ?, replaced_by = ? WHERE"
+                        " room_id = ? AND invitee = ? AND locally_rejected is NULL"
+                        " AND replaced_by is NULL"
+                    )
+
+                    txn.execute(
+                        sql,
+                        (
+                            event.internal_metadata.stream_ordering,
+                            event.event_id,
+                            event.room_id,
+                            event.state_key,
+                        ),
+                    )
+
+    @defer.inlineCallbacks
+    def locally_reject_invite(self, user_id, room_id):
+        sql = (
+            "UPDATE local_invites SET stream_id = ?, locally_rejected = ? WHERE"
+            " room_id = ? AND invitee = ? AND locally_rejected is NULL"
+            " AND replaced_by is NULL"
+        )
+
+        def f(txn, stream_ordering):
+            txn.execute(sql, (stream_ordering, True, room_id, user_id))
+
+        with self._stream_id_gen.get_next() as stream_ordering:
+            yield self.runInteraction("locally_reject_invite", f, stream_ordering)
+
+    def forget(self, user_id, room_id):
+        """Indicate that user_id wishes to discard history for room_id."""
+
+        def f(txn):
+            sql = (
+                "UPDATE"
+                "  room_memberships"
+                " SET"
+                "  forgotten = 1"
+                " WHERE"
+                "  user_id = ?"
+                " AND"
+                "  room_id = ?"
+            )
+            txn.execute(sql, (user_id, room_id))
+
+            self._invalidate_cache_and_stream(txn, self.did_forget, (user_id, room_id))
+            self._invalidate_cache_and_stream(
+                txn, self.get_forgotten_rooms_for_user, (user_id,)
+            )
+
+        return self.runInteraction("forget_membership", f)
+
+
+class _JoinedHostsCache(object):
+    """Cache for joined hosts in a room that is optimised to handle updates
+    via state deltas.
+    """
+
+    def __init__(self, store, room_id):
+        self.store = store
+        self.room_id = room_id
+
+        self.hosts_to_joined_users = {}
+
+        self.state_group = object()
+
+        self.linearizer = Linearizer("_JoinedHostsCache")
+
+        self._len = 0
+
+    @defer.inlineCallbacks
+    def get_destinations(self, state_entry):
+        """Get set of destinations for a state entry
+
+        Args:
+            state_entry(synapse.state._StateCacheEntry)
+        """
+        if state_entry.state_group == self.state_group:
+            return frozenset(self.hosts_to_joined_users)
+
+        with (yield self.linearizer.queue(())):
+            if state_entry.state_group == self.state_group:
+                pass
+            elif state_entry.prev_group == self.state_group:
+                for (typ, state_key), event_id in iteritems(state_entry.delta_ids):
+                    if typ != EventTypes.Member:
+                        continue
+
+                    host = intern_string(get_domain_from_id(state_key))
+                    user_id = state_key
+                    known_joins = self.hosts_to_joined_users.setdefault(host, set())
+
+                    event = yield self.store.get_event(event_id)
+                    if event.membership == Membership.JOIN:
+                        known_joins.add(user_id)
+                    else:
+                        known_joins.discard(user_id)
+
+                        if not known_joins:
+                            self.hosts_to_joined_users.pop(host, None)
+            else:
+                joined_users = yield self.store.get_joined_users_from_state(
+                    self.room_id, state_entry
+                )
+
+                self.hosts_to_joined_users = {}
+                for user_id in joined_users:
+                    host = intern_string(get_domain_from_id(user_id))
+                    self.hosts_to_joined_users.setdefault(host, set()).add(user_id)
+
+            if state_entry.state_group:
+                self.state_group = state_entry.state_group
+            else:
+                self.state_group = object()
+            self._len = sum(len(v) for v in itervalues(self.hosts_to_joined_users))
+        return frozenset(self.hosts_to_joined_users)
+
+    def __len__(self):
+        return self._len
diff --git a/synapse/storage/schema/delta/12/v12.sql b/synapse/storage/data_stores/main/schema/delta/12/v12.sql
index 5964c5aaac..5964c5aaac 100644
--- a/synapse/storage/schema/delta/12/v12.sql
+++ b/synapse/storage/data_stores/main/schema/delta/12/v12.sql
diff --git a/synapse/storage/schema/delta/13/v13.sql b/synapse/storage/data_stores/main/schema/delta/13/v13.sql
index f8649e5d99..f8649e5d99 100644
--- a/synapse/storage/schema/delta/13/v13.sql
+++ b/synapse/storage/data_stores/main/schema/delta/13/v13.sql
diff --git a/synapse/storage/schema/delta/14/v14.sql b/synapse/storage/data_stores/main/schema/delta/14/v14.sql
index a831920da6..a831920da6 100644
--- a/synapse/storage/schema/delta/14/v14.sql
+++ b/synapse/storage/data_stores/main/schema/delta/14/v14.sql
diff --git a/synapse/storage/schema/delta/15/appservice_txns.sql b/synapse/storage/data_stores/main/schema/delta/15/appservice_txns.sql
index e4f5e76aec..e4f5e76aec 100644
--- a/synapse/storage/schema/delta/15/appservice_txns.sql
+++ b/synapse/storage/data_stores/main/schema/delta/15/appservice_txns.sql
diff --git a/synapse/storage/schema/delta/15/presence_indices.sql b/synapse/storage/data_stores/main/schema/delta/15/presence_indices.sql
index 6b8d0f1ca7..6b8d0f1ca7 100644
--- a/synapse/storage/schema/delta/15/presence_indices.sql
+++ b/synapse/storage/data_stores/main/schema/delta/15/presence_indices.sql
diff --git a/synapse/storage/schema/delta/15/v15.sql b/synapse/storage/data_stores/main/schema/delta/15/v15.sql
index 9523d2bcc3..9523d2bcc3 100644
--- a/synapse/storage/schema/delta/15/v15.sql
+++ b/synapse/storage/data_stores/main/schema/delta/15/v15.sql
diff --git a/synapse/storage/schema/delta/16/events_order_index.sql b/synapse/storage/data_stores/main/schema/delta/16/events_order_index.sql
index a48f215170..a48f215170 100644
--- a/synapse/storage/schema/delta/16/events_order_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/16/events_order_index.sql
diff --git a/synapse/storage/schema/delta/16/remote_media_cache_index.sql b/synapse/storage/data_stores/main/schema/delta/16/remote_media_cache_index.sql
index 7a15265cb1..7a15265cb1 100644
--- a/synapse/storage/schema/delta/16/remote_media_cache_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/16/remote_media_cache_index.sql
diff --git a/synapse/storage/schema/delta/16/remove_duplicates.sql b/synapse/storage/data_stores/main/schema/delta/16/remove_duplicates.sql
index 65c97b5e2f..65c97b5e2f 100644
--- a/synapse/storage/schema/delta/16/remove_duplicates.sql
+++ b/synapse/storage/data_stores/main/schema/delta/16/remove_duplicates.sql
diff --git a/synapse/storage/schema/delta/16/room_alias_index.sql b/synapse/storage/data_stores/main/schema/delta/16/room_alias_index.sql
index f82486132b..f82486132b 100644
--- a/synapse/storage/schema/delta/16/room_alias_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/16/room_alias_index.sql
diff --git a/synapse/storage/schema/delta/16/unique_constraints.sql b/synapse/storage/data_stores/main/schema/delta/16/unique_constraints.sql
index 5b8de52c33..5b8de52c33 100644
--- a/synapse/storage/schema/delta/16/unique_constraints.sql
+++ b/synapse/storage/data_stores/main/schema/delta/16/unique_constraints.sql
diff --git a/synapse/storage/schema/delta/16/users.sql b/synapse/storage/data_stores/main/schema/delta/16/users.sql
index cd0709250d..cd0709250d 100644
--- a/synapse/storage/schema/delta/16/users.sql
+++ b/synapse/storage/data_stores/main/schema/delta/16/users.sql
diff --git a/synapse/storage/schema/delta/17/drop_indexes.sql b/synapse/storage/data_stores/main/schema/delta/17/drop_indexes.sql
index 7c9a90e27f..7c9a90e27f 100644
--- a/synapse/storage/schema/delta/17/drop_indexes.sql
+++ b/synapse/storage/data_stores/main/schema/delta/17/drop_indexes.sql
diff --git a/synapse/storage/schema/delta/17/server_keys.sql b/synapse/storage/data_stores/main/schema/delta/17/server_keys.sql
index 70b247a06b..70b247a06b 100644
--- a/synapse/storage/schema/delta/17/server_keys.sql
+++ b/synapse/storage/data_stores/main/schema/delta/17/server_keys.sql
diff --git a/synapse/storage/schema/delta/17/user_threepids.sql b/synapse/storage/data_stores/main/schema/delta/17/user_threepids.sql
index c17715ac80..c17715ac80 100644
--- a/synapse/storage/schema/delta/17/user_threepids.sql
+++ b/synapse/storage/data_stores/main/schema/delta/17/user_threepids.sql
diff --git a/synapse/storage/schema/delta/18/server_keys_bigger_ints.sql b/synapse/storage/data_stores/main/schema/delta/18/server_keys_bigger_ints.sql
index 6e0871c92b..6e0871c92b 100644
--- a/synapse/storage/schema/delta/18/server_keys_bigger_ints.sql
+++ b/synapse/storage/data_stores/main/schema/delta/18/server_keys_bigger_ints.sql
diff --git a/synapse/storage/schema/delta/19/event_index.sql b/synapse/storage/data_stores/main/schema/delta/19/event_index.sql
index 18b97b4332..18b97b4332 100644
--- a/synapse/storage/schema/delta/19/event_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/19/event_index.sql
diff --git a/synapse/storage/schema/delta/20/dummy.sql b/synapse/storage/data_stores/main/schema/delta/20/dummy.sql
index e0ac49d1ec..e0ac49d1ec 100644
--- a/synapse/storage/schema/delta/20/dummy.sql
+++ b/synapse/storage/data_stores/main/schema/delta/20/dummy.sql
diff --git a/synapse/storage/schema/delta/20/pushers.py b/synapse/storage/data_stores/main/schema/delta/20/pushers.py
index 3edfcfd783..3edfcfd783 100644
--- a/synapse/storage/schema/delta/20/pushers.py
+++ b/synapse/storage/data_stores/main/schema/delta/20/pushers.py
diff --git a/synapse/storage/schema/delta/21/end_to_end_keys.sql b/synapse/storage/data_stores/main/schema/delta/21/end_to_end_keys.sql
index 4c2fb20b77..4c2fb20b77 100644
--- a/synapse/storage/schema/delta/21/end_to_end_keys.sql
+++ b/synapse/storage/data_stores/main/schema/delta/21/end_to_end_keys.sql
diff --git a/synapse/storage/schema/delta/21/receipts.sql b/synapse/storage/data_stores/main/schema/delta/21/receipts.sql
index d070845477..d070845477 100644
--- a/synapse/storage/schema/delta/21/receipts.sql
+++ b/synapse/storage/data_stores/main/schema/delta/21/receipts.sql
diff --git a/synapse/storage/schema/delta/22/receipts_index.sql b/synapse/storage/data_stores/main/schema/delta/22/receipts_index.sql
index bfc0b3bcaa..bfc0b3bcaa 100644
--- a/synapse/storage/schema/delta/22/receipts_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/22/receipts_index.sql
diff --git a/synapse/storage/schema/delta/22/user_threepids_unique.sql b/synapse/storage/data_stores/main/schema/delta/22/user_threepids_unique.sql
index 87edfa454c..87edfa454c 100644
--- a/synapse/storage/schema/delta/22/user_threepids_unique.sql
+++ b/synapse/storage/data_stores/main/schema/delta/22/user_threepids_unique.sql
diff --git a/synapse/storage/schema/delta/23/drop_state_index.sql b/synapse/storage/data_stores/main/schema/delta/23/drop_state_index.sql
index ae09fa0065..ae09fa0065 100644
--- a/synapse/storage/schema/delta/23/drop_state_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/23/drop_state_index.sql
diff --git a/synapse/storage/schema/delta/24/stats_reporting.sql b/synapse/storage/data_stores/main/schema/delta/24/stats_reporting.sql
index acea7483bd..acea7483bd 100644
--- a/synapse/storage/schema/delta/24/stats_reporting.sql
+++ b/synapse/storage/data_stores/main/schema/delta/24/stats_reporting.sql
diff --git a/synapse/storage/schema/delta/25/fts.py b/synapse/storage/data_stores/main/schema/delta/25/fts.py
index 4b2ffd35fd..4b2ffd35fd 100644
--- a/synapse/storage/schema/delta/25/fts.py
+++ b/synapse/storage/data_stores/main/schema/delta/25/fts.py
diff --git a/synapse/storage/schema/delta/25/guest_access.sql b/synapse/storage/data_stores/main/schema/delta/25/guest_access.sql
index 1ea389b471..1ea389b471 100644
--- a/synapse/storage/schema/delta/25/guest_access.sql
+++ b/synapse/storage/data_stores/main/schema/delta/25/guest_access.sql
diff --git a/synapse/storage/schema/delta/25/history_visibility.sql b/synapse/storage/data_stores/main/schema/delta/25/history_visibility.sql
index f468fc1897..f468fc1897 100644
--- a/synapse/storage/schema/delta/25/history_visibility.sql
+++ b/synapse/storage/data_stores/main/schema/delta/25/history_visibility.sql
diff --git a/synapse/storage/schema/delta/25/tags.sql b/synapse/storage/data_stores/main/schema/delta/25/tags.sql
index 7a32ce68e4..7a32ce68e4 100644
--- a/synapse/storage/schema/delta/25/tags.sql
+++ b/synapse/storage/data_stores/main/schema/delta/25/tags.sql
diff --git a/synapse/storage/schema/delta/26/account_data.sql b/synapse/storage/data_stores/main/schema/delta/26/account_data.sql
index e395de2b5e..e395de2b5e 100644
--- a/synapse/storage/schema/delta/26/account_data.sql
+++ b/synapse/storage/data_stores/main/schema/delta/26/account_data.sql
diff --git a/synapse/storage/schema/delta/27/account_data.sql b/synapse/storage/data_stores/main/schema/delta/27/account_data.sql
index bf0558b5b3..bf0558b5b3 100644
--- a/synapse/storage/schema/delta/27/account_data.sql
+++ b/synapse/storage/data_stores/main/schema/delta/27/account_data.sql
diff --git a/synapse/storage/schema/delta/27/forgotten_memberships.sql b/synapse/storage/data_stores/main/schema/delta/27/forgotten_memberships.sql
index e2094f37fe..e2094f37fe 100644
--- a/synapse/storage/schema/delta/27/forgotten_memberships.sql
+++ b/synapse/storage/data_stores/main/schema/delta/27/forgotten_memberships.sql
diff --git a/synapse/storage/schema/delta/27/ts.py b/synapse/storage/data_stores/main/schema/delta/27/ts.py
index 414f9f5aa0..414f9f5aa0 100644
--- a/synapse/storage/schema/delta/27/ts.py
+++ b/synapse/storage/data_stores/main/schema/delta/27/ts.py
diff --git a/synapse/storage/schema/delta/28/event_push_actions.sql b/synapse/storage/data_stores/main/schema/delta/28/event_push_actions.sql
index 4d519849df..4d519849df 100644
--- a/synapse/storage/schema/delta/28/event_push_actions.sql
+++ b/synapse/storage/data_stores/main/schema/delta/28/event_push_actions.sql
diff --git a/synapse/storage/schema/delta/28/events_room_stream.sql b/synapse/storage/data_stores/main/schema/delta/28/events_room_stream.sql
index 36609475f1..36609475f1 100644
--- a/synapse/storage/schema/delta/28/events_room_stream.sql
+++ b/synapse/storage/data_stores/main/schema/delta/28/events_room_stream.sql
diff --git a/synapse/storage/schema/delta/28/public_roms_index.sql b/synapse/storage/data_stores/main/schema/delta/28/public_roms_index.sql
index 6c1fd68c5b..6c1fd68c5b 100644
--- a/synapse/storage/schema/delta/28/public_roms_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/28/public_roms_index.sql
diff --git a/synapse/storage/schema/delta/28/receipts_user_id_index.sql b/synapse/storage/data_stores/main/schema/delta/28/receipts_user_id_index.sql
index cb84c69baa..cb84c69baa 100644
--- a/synapse/storage/schema/delta/28/receipts_user_id_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/28/receipts_user_id_index.sql
diff --git a/synapse/storage/schema/delta/28/upgrade_times.sql b/synapse/storage/data_stores/main/schema/delta/28/upgrade_times.sql
index 3e4a9ab455..3e4a9ab455 100644
--- a/synapse/storage/schema/delta/28/upgrade_times.sql
+++ b/synapse/storage/data_stores/main/schema/delta/28/upgrade_times.sql
diff --git a/synapse/storage/schema/delta/28/users_is_guest.sql b/synapse/storage/data_stores/main/schema/delta/28/users_is_guest.sql
index 21d2b420bf..21d2b420bf 100644
--- a/synapse/storage/schema/delta/28/users_is_guest.sql
+++ b/synapse/storage/data_stores/main/schema/delta/28/users_is_guest.sql
diff --git a/synapse/storage/schema/delta/29/push_actions.sql b/synapse/storage/data_stores/main/schema/delta/29/push_actions.sql
index 84b21cf813..84b21cf813 100644
--- a/synapse/storage/schema/delta/29/push_actions.sql
+++ b/synapse/storage/data_stores/main/schema/delta/29/push_actions.sql
diff --git a/synapse/storage/schema/delta/30/alias_creator.sql b/synapse/storage/data_stores/main/schema/delta/30/alias_creator.sql
index c9d0dde638..c9d0dde638 100644
--- a/synapse/storage/schema/delta/30/alias_creator.sql
+++ b/synapse/storage/data_stores/main/schema/delta/30/alias_creator.sql
diff --git a/synapse/storage/schema/delta/30/as_users.py b/synapse/storage/data_stores/main/schema/delta/30/as_users.py
index 9b95411fb6..9b95411fb6 100644
--- a/synapse/storage/schema/delta/30/as_users.py
+++ b/synapse/storage/data_stores/main/schema/delta/30/as_users.py
diff --git a/synapse/storage/schema/delta/30/deleted_pushers.sql b/synapse/storage/data_stores/main/schema/delta/30/deleted_pushers.sql
index 712c454aa1..712c454aa1 100644
--- a/synapse/storage/schema/delta/30/deleted_pushers.sql
+++ b/synapse/storage/data_stores/main/schema/delta/30/deleted_pushers.sql
diff --git a/synapse/storage/schema/delta/30/presence_stream.sql b/synapse/storage/data_stores/main/schema/delta/30/presence_stream.sql
index 606bbb037d..606bbb037d 100644
--- a/synapse/storage/schema/delta/30/presence_stream.sql
+++ b/synapse/storage/data_stores/main/schema/delta/30/presence_stream.sql
diff --git a/synapse/storage/schema/delta/30/public_rooms.sql b/synapse/storage/data_stores/main/schema/delta/30/public_rooms.sql
index f09db4faa6..f09db4faa6 100644
--- a/synapse/storage/schema/delta/30/public_rooms.sql
+++ b/synapse/storage/data_stores/main/schema/delta/30/public_rooms.sql
diff --git a/synapse/storage/schema/delta/30/push_rule_stream.sql b/synapse/storage/data_stores/main/schema/delta/30/push_rule_stream.sql
index 735aa8d5f6..735aa8d5f6 100644
--- a/synapse/storage/schema/delta/30/push_rule_stream.sql
+++ b/synapse/storage/data_stores/main/schema/delta/30/push_rule_stream.sql
diff --git a/synapse/storage/schema/delta/30/state_stream.sql b/synapse/storage/data_stores/main/schema/delta/30/state_stream.sql
index e85699e82e..e85699e82e 100644
--- a/synapse/storage/schema/delta/30/state_stream.sql
+++ b/synapse/storage/data_stores/main/schema/delta/30/state_stream.sql
diff --git a/synapse/storage/schema/delta/30/threepid_guest_access_tokens.sql b/synapse/storage/data_stores/main/schema/delta/30/threepid_guest_access_tokens.sql
index 0dd2f1360c..0dd2f1360c 100644
--- a/synapse/storage/schema/delta/30/threepid_guest_access_tokens.sql
+++ b/synapse/storage/data_stores/main/schema/delta/30/threepid_guest_access_tokens.sql
diff --git a/synapse/storage/schema/delta/31/invites.sql b/synapse/storage/data_stores/main/schema/delta/31/invites.sql
index 2c57846d5a..2c57846d5a 100644
--- a/synapse/storage/schema/delta/31/invites.sql
+++ b/synapse/storage/data_stores/main/schema/delta/31/invites.sql
diff --git a/synapse/storage/schema/delta/31/local_media_repository_url_cache.sql b/synapse/storage/data_stores/main/schema/delta/31/local_media_repository_url_cache.sql
index 9efb4280eb..9efb4280eb 100644
--- a/synapse/storage/schema/delta/31/local_media_repository_url_cache.sql
+++ b/synapse/storage/data_stores/main/schema/delta/31/local_media_repository_url_cache.sql
diff --git a/synapse/storage/schema/delta/31/pushers.py b/synapse/storage/data_stores/main/schema/delta/31/pushers.py
index 9bb504aad5..9bb504aad5 100644
--- a/synapse/storage/schema/delta/31/pushers.py
+++ b/synapse/storage/data_stores/main/schema/delta/31/pushers.py
diff --git a/synapse/storage/schema/delta/31/pushers_index.sql b/synapse/storage/data_stores/main/schema/delta/31/pushers_index.sql
index a82add88fd..a82add88fd 100644
--- a/synapse/storage/schema/delta/31/pushers_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/31/pushers_index.sql
diff --git a/synapse/storage/schema/delta/31/search_update.py b/synapse/storage/data_stores/main/schema/delta/31/search_update.py
index 7d8ca5f93f..7d8ca5f93f 100644
--- a/synapse/storage/schema/delta/31/search_update.py
+++ b/synapse/storage/data_stores/main/schema/delta/31/search_update.py
diff --git a/synapse/storage/schema/delta/32/events.sql b/synapse/storage/data_stores/main/schema/delta/32/events.sql
index 1dd0f9e170..1dd0f9e170 100644
--- a/synapse/storage/schema/delta/32/events.sql
+++ b/synapse/storage/data_stores/main/schema/delta/32/events.sql
diff --git a/synapse/storage/schema/delta/32/openid.sql b/synapse/storage/data_stores/main/schema/delta/32/openid.sql
index 36f37b11c8..36f37b11c8 100644
--- a/synapse/storage/schema/delta/32/openid.sql
+++ b/synapse/storage/data_stores/main/schema/delta/32/openid.sql
diff --git a/synapse/storage/schema/delta/32/pusher_throttle.sql b/synapse/storage/data_stores/main/schema/delta/32/pusher_throttle.sql
index d86d30c13c..d86d30c13c 100644
--- a/synapse/storage/schema/delta/32/pusher_throttle.sql
+++ b/synapse/storage/data_stores/main/schema/delta/32/pusher_throttle.sql
diff --git a/synapse/storage/schema/delta/32/remove_indices.sql b/synapse/storage/data_stores/main/schema/delta/32/remove_indices.sql
index 4219cdd06a..4219cdd06a 100644
--- a/synapse/storage/schema/delta/32/remove_indices.sql
+++ b/synapse/storage/data_stores/main/schema/delta/32/remove_indices.sql
diff --git a/synapse/storage/schema/delta/32/reports.sql b/synapse/storage/data_stores/main/schema/delta/32/reports.sql
index d13609776f..d13609776f 100644
--- a/synapse/storage/schema/delta/32/reports.sql
+++ b/synapse/storage/data_stores/main/schema/delta/32/reports.sql
diff --git a/synapse/storage/schema/delta/33/access_tokens_device_index.sql b/synapse/storage/data_stores/main/schema/delta/33/access_tokens_device_index.sql
index 61ad3fe3e8..61ad3fe3e8 100644
--- a/synapse/storage/schema/delta/33/access_tokens_device_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/33/access_tokens_device_index.sql
diff --git a/synapse/storage/schema/delta/33/devices.sql b/synapse/storage/data_stores/main/schema/delta/33/devices.sql
index eca7268d82..eca7268d82 100644
--- a/synapse/storage/schema/delta/33/devices.sql
+++ b/synapse/storage/data_stores/main/schema/delta/33/devices.sql
diff --git a/synapse/storage/schema/delta/33/devices_for_e2e_keys.sql b/synapse/storage/data_stores/main/schema/delta/33/devices_for_e2e_keys.sql
index aa4a3b9f2f..aa4a3b9f2f 100644
--- a/synapse/storage/schema/delta/33/devices_for_e2e_keys.sql
+++ b/synapse/storage/data_stores/main/schema/delta/33/devices_for_e2e_keys.sql
diff --git a/synapse/storage/schema/delta/33/devices_for_e2e_keys_clear_unknown_device.sql b/synapse/storage/data_stores/main/schema/delta/33/devices_for_e2e_keys_clear_unknown_device.sql
index 6671573398..6671573398 100644
--- a/synapse/storage/schema/delta/33/devices_for_e2e_keys_clear_unknown_device.sql
+++ b/synapse/storage/data_stores/main/schema/delta/33/devices_for_e2e_keys_clear_unknown_device.sql
diff --git a/synapse/storage/schema/delta/33/event_fields.py b/synapse/storage/data_stores/main/schema/delta/33/event_fields.py
index bff1256a7b..bff1256a7b 100644
--- a/synapse/storage/schema/delta/33/event_fields.py
+++ b/synapse/storage/data_stores/main/schema/delta/33/event_fields.py
diff --git a/synapse/storage/schema/delta/33/remote_media_ts.py b/synapse/storage/data_stores/main/schema/delta/33/remote_media_ts.py
index a26057dfb6..a26057dfb6 100644
--- a/synapse/storage/schema/delta/33/remote_media_ts.py
+++ b/synapse/storage/data_stores/main/schema/delta/33/remote_media_ts.py
diff --git a/synapse/storage/schema/delta/33/user_ips_index.sql b/synapse/storage/data_stores/main/schema/delta/33/user_ips_index.sql
index 473f75a78e..473f75a78e 100644
--- a/synapse/storage/schema/delta/33/user_ips_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/33/user_ips_index.sql
diff --git a/synapse/storage/schema/delta/34/appservice_stream.sql b/synapse/storage/data_stores/main/schema/delta/34/appservice_stream.sql
index 69e16eda0f..69e16eda0f 100644
--- a/synapse/storage/schema/delta/34/appservice_stream.sql
+++ b/synapse/storage/data_stores/main/schema/delta/34/appservice_stream.sql
diff --git a/synapse/storage/schema/delta/34/cache_stream.py b/synapse/storage/data_stores/main/schema/delta/34/cache_stream.py
index cf09e43e2b..cf09e43e2b 100644
--- a/synapse/storage/schema/delta/34/cache_stream.py
+++ b/synapse/storage/data_stores/main/schema/delta/34/cache_stream.py
diff --git a/synapse/storage/schema/delta/34/device_inbox.sql b/synapse/storage/data_stores/main/schema/delta/34/device_inbox.sql
index e68844c74a..e68844c74a 100644
--- a/synapse/storage/schema/delta/34/device_inbox.sql
+++ b/synapse/storage/data_stores/main/schema/delta/34/device_inbox.sql
diff --git a/synapse/storage/schema/delta/34/push_display_name_rename.sql b/synapse/storage/data_stores/main/schema/delta/34/push_display_name_rename.sql
index 0d9fe1a99a..0d9fe1a99a 100644
--- a/synapse/storage/schema/delta/34/push_display_name_rename.sql
+++ b/synapse/storage/data_stores/main/schema/delta/34/push_display_name_rename.sql
diff --git a/synapse/storage/schema/delta/34/received_txn_purge.py b/synapse/storage/data_stores/main/schema/delta/34/received_txn_purge.py
index 67d505e68b..67d505e68b 100644
--- a/synapse/storage/schema/delta/34/received_txn_purge.py
+++ b/synapse/storage/data_stores/main/schema/delta/34/received_txn_purge.py
diff --git a/synapse/storage/schema/delta/35/add_state_index.sql b/synapse/storage/data_stores/main/schema/delta/35/add_state_index.sql
index 0fce26345b..33980d02f0 100644
--- a/synapse/storage/schema/delta/35/add_state_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/add_state_index.sql
@@ -13,8 +13,5 @@
  * limitations under the License.
  */
 
-
-ALTER TABLE background_updates ADD COLUMN depends_on TEXT;
-
 INSERT into background_updates (update_name, progress_json, depends_on)
     VALUES ('state_group_state_type_index', '{}', 'state_group_state_deduplication');
diff --git a/synapse/storage/schema/delta/35/contains_url.sql b/synapse/storage/data_stores/main/schema/delta/35/contains_url.sql
index 6cd123027b..6cd123027b 100644
--- a/synapse/storage/schema/delta/35/contains_url.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/contains_url.sql
diff --git a/synapse/storage/schema/delta/35/device_outbox.sql b/synapse/storage/data_stores/main/schema/delta/35/device_outbox.sql
index 17e6c43105..17e6c43105 100644
--- a/synapse/storage/schema/delta/35/device_outbox.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/device_outbox.sql
diff --git a/synapse/storage/schema/delta/35/device_stream_id.sql b/synapse/storage/data_stores/main/schema/delta/35/device_stream_id.sql
index 7ab7d942e2..7ab7d942e2 100644
--- a/synapse/storage/schema/delta/35/device_stream_id.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/device_stream_id.sql
diff --git a/synapse/storage/schema/delta/35/event_push_actions_index.sql b/synapse/storage/data_stores/main/schema/delta/35/event_push_actions_index.sql
index 2e836d8e9c..2e836d8e9c 100644
--- a/synapse/storage/schema/delta/35/event_push_actions_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/event_push_actions_index.sql
diff --git a/synapse/storage/schema/delta/35/public_room_list_change_stream.sql b/synapse/storage/data_stores/main/schema/delta/35/public_room_list_change_stream.sql
index dd2bf2e28a..dd2bf2e28a 100644
--- a/synapse/storage/schema/delta/35/public_room_list_change_stream.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/public_room_list_change_stream.sql
diff --git a/synapse/storage/schema/delta/35/state.sql b/synapse/storage/data_stores/main/schema/delta/35/state.sql
index 0f1fa68a89..0f1fa68a89 100644
--- a/synapse/storage/schema/delta/35/state.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/state.sql
diff --git a/synapse/storage/schema/delta/35/state_dedupe.sql b/synapse/storage/data_stores/main/schema/delta/35/state_dedupe.sql
index 97e5067ef4..97e5067ef4 100644
--- a/synapse/storage/schema/delta/35/state_dedupe.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/state_dedupe.sql
diff --git a/synapse/storage/schema/delta/35/stream_order_to_extrem.sql b/synapse/storage/data_stores/main/schema/delta/35/stream_order_to_extrem.sql
index 2b945d8a57..2b945d8a57 100644
--- a/synapse/storage/schema/delta/35/stream_order_to_extrem.sql
+++ b/synapse/storage/data_stores/main/schema/delta/35/stream_order_to_extrem.sql
diff --git a/synapse/storage/schema/delta/36/readd_public_rooms.sql b/synapse/storage/data_stores/main/schema/delta/36/readd_public_rooms.sql
index 90d8fd18f9..90d8fd18f9 100644
--- a/synapse/storage/schema/delta/36/readd_public_rooms.sql
+++ b/synapse/storage/data_stores/main/schema/delta/36/readd_public_rooms.sql
diff --git a/synapse/storage/schema/delta/37/remove_auth_idx.py b/synapse/storage/data_stores/main/schema/delta/37/remove_auth_idx.py
index a377884169..a377884169 100644
--- a/synapse/storage/schema/delta/37/remove_auth_idx.py
+++ b/synapse/storage/data_stores/main/schema/delta/37/remove_auth_idx.py
diff --git a/synapse/storage/schema/delta/37/user_threepids.sql b/synapse/storage/data_stores/main/schema/delta/37/user_threepids.sql
index cf7a90dd10..cf7a90dd10 100644
--- a/synapse/storage/schema/delta/37/user_threepids.sql
+++ b/synapse/storage/data_stores/main/schema/delta/37/user_threepids.sql
diff --git a/synapse/storage/schema/delta/38/postgres_fts_gist.sql b/synapse/storage/data_stores/main/schema/delta/38/postgres_fts_gist.sql
index 515e6b8e84..515e6b8e84 100644
--- a/synapse/storage/schema/delta/38/postgres_fts_gist.sql
+++ b/synapse/storage/data_stores/main/schema/delta/38/postgres_fts_gist.sql
diff --git a/synapse/storage/schema/delta/39/appservice_room_list.sql b/synapse/storage/data_stores/main/schema/delta/39/appservice_room_list.sql
index 74bdc49073..74bdc49073 100644
--- a/synapse/storage/schema/delta/39/appservice_room_list.sql
+++ b/synapse/storage/data_stores/main/schema/delta/39/appservice_room_list.sql
diff --git a/synapse/storage/schema/delta/39/device_federation_stream_idx.sql b/synapse/storage/data_stores/main/schema/delta/39/device_federation_stream_idx.sql
index 00be801e90..00be801e90 100644
--- a/synapse/storage/schema/delta/39/device_federation_stream_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/39/device_federation_stream_idx.sql
diff --git a/synapse/storage/schema/delta/39/event_push_index.sql b/synapse/storage/data_stores/main/schema/delta/39/event_push_index.sql
index de2ad93e5c..de2ad93e5c 100644
--- a/synapse/storage/schema/delta/39/event_push_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/39/event_push_index.sql
diff --git a/synapse/storage/schema/delta/39/federation_out_position.sql b/synapse/storage/data_stores/main/schema/delta/39/federation_out_position.sql
index 5af814290b..5af814290b 100644
--- a/synapse/storage/schema/delta/39/federation_out_position.sql
+++ b/synapse/storage/data_stores/main/schema/delta/39/federation_out_position.sql
diff --git a/synapse/storage/schema/delta/39/membership_profile.sql b/synapse/storage/data_stores/main/schema/delta/39/membership_profile.sql
index 1bf911c8ab..1bf911c8ab 100644
--- a/synapse/storage/schema/delta/39/membership_profile.sql
+++ b/synapse/storage/data_stores/main/schema/delta/39/membership_profile.sql
diff --git a/synapse/storage/schema/delta/40/current_state_idx.sql b/synapse/storage/data_stores/main/schema/delta/40/current_state_idx.sql
index 7ffa189f39..7ffa189f39 100644
--- a/synapse/storage/schema/delta/40/current_state_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/40/current_state_idx.sql
diff --git a/synapse/storage/schema/delta/40/device_inbox.sql b/synapse/storage/data_stores/main/schema/delta/40/device_inbox.sql
index b9fe1f0480..b9fe1f0480 100644
--- a/synapse/storage/schema/delta/40/device_inbox.sql
+++ b/synapse/storage/data_stores/main/schema/delta/40/device_inbox.sql
diff --git a/synapse/storage/schema/delta/40/device_list_streams.sql b/synapse/storage/data_stores/main/schema/delta/40/device_list_streams.sql
index dd6dcb65f1..dd6dcb65f1 100644
--- a/synapse/storage/schema/delta/40/device_list_streams.sql
+++ b/synapse/storage/data_stores/main/schema/delta/40/device_list_streams.sql
diff --git a/synapse/storage/schema/delta/40/event_push_summary.sql b/synapse/storage/data_stores/main/schema/delta/40/event_push_summary.sql
index 3918f0b794..3918f0b794 100644
--- a/synapse/storage/schema/delta/40/event_push_summary.sql
+++ b/synapse/storage/data_stores/main/schema/delta/40/event_push_summary.sql
diff --git a/synapse/storage/schema/delta/40/pushers.sql b/synapse/storage/data_stores/main/schema/delta/40/pushers.sql
index 054a223f14..054a223f14 100644
--- a/synapse/storage/schema/delta/40/pushers.sql
+++ b/synapse/storage/data_stores/main/schema/delta/40/pushers.sql
diff --git a/synapse/storage/schema/delta/41/device_list_stream_idx.sql b/synapse/storage/data_stores/main/schema/delta/41/device_list_stream_idx.sql
index b7bee8b692..b7bee8b692 100644
--- a/synapse/storage/schema/delta/41/device_list_stream_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/41/device_list_stream_idx.sql
diff --git a/synapse/storage/schema/delta/41/device_outbound_index.sql b/synapse/storage/data_stores/main/schema/delta/41/device_outbound_index.sql
index 62f0b9892b..62f0b9892b 100644
--- a/synapse/storage/schema/delta/41/device_outbound_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/41/device_outbound_index.sql
diff --git a/synapse/storage/schema/delta/41/event_search_event_id_idx.sql b/synapse/storage/data_stores/main/schema/delta/41/event_search_event_id_idx.sql
index 5d9cfecf36..5d9cfecf36 100644
--- a/synapse/storage/schema/delta/41/event_search_event_id_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/41/event_search_event_id_idx.sql
diff --git a/synapse/storage/schema/delta/41/ratelimit.sql b/synapse/storage/data_stores/main/schema/delta/41/ratelimit.sql
index a194bf0238..a194bf0238 100644
--- a/synapse/storage/schema/delta/41/ratelimit.sql
+++ b/synapse/storage/data_stores/main/schema/delta/41/ratelimit.sql
diff --git a/synapse/storage/schema/delta/42/current_state_delta.sql b/synapse/storage/data_stores/main/schema/delta/42/current_state_delta.sql
index d28851aff8..d28851aff8 100644
--- a/synapse/storage/schema/delta/42/current_state_delta.sql
+++ b/synapse/storage/data_stores/main/schema/delta/42/current_state_delta.sql
diff --git a/synapse/storage/schema/delta/42/device_list_last_id.sql b/synapse/storage/data_stores/main/schema/delta/42/device_list_last_id.sql
index 9ab8c14fa3..9ab8c14fa3 100644
--- a/synapse/storage/schema/delta/42/device_list_last_id.sql
+++ b/synapse/storage/data_stores/main/schema/delta/42/device_list_last_id.sql
diff --git a/synapse/storage/schema/delta/42/event_auth_state_only.sql b/synapse/storage/data_stores/main/schema/delta/42/event_auth_state_only.sql
index b8821ac759..b8821ac759 100644
--- a/synapse/storage/schema/delta/42/event_auth_state_only.sql
+++ b/synapse/storage/data_stores/main/schema/delta/42/event_auth_state_only.sql
diff --git a/synapse/storage/schema/delta/42/user_dir.py b/synapse/storage/data_stores/main/schema/delta/42/user_dir.py
index 506f326f4d..506f326f4d 100644
--- a/synapse/storage/schema/delta/42/user_dir.py
+++ b/synapse/storage/data_stores/main/schema/delta/42/user_dir.py
diff --git a/synapse/storage/schema/delta/43/blocked_rooms.sql b/synapse/storage/data_stores/main/schema/delta/43/blocked_rooms.sql
index 0e3cd143ff..0e3cd143ff 100644
--- a/synapse/storage/schema/delta/43/blocked_rooms.sql
+++ b/synapse/storage/data_stores/main/schema/delta/43/blocked_rooms.sql
diff --git a/synapse/storage/schema/delta/43/quarantine_media.sql b/synapse/storage/data_stores/main/schema/delta/43/quarantine_media.sql
index 630907ec4f..630907ec4f 100644
--- a/synapse/storage/schema/delta/43/quarantine_media.sql
+++ b/synapse/storage/data_stores/main/schema/delta/43/quarantine_media.sql
diff --git a/synapse/storage/schema/delta/43/url_cache.sql b/synapse/storage/data_stores/main/schema/delta/43/url_cache.sql
index 45ebe020da..45ebe020da 100644
--- a/synapse/storage/schema/delta/43/url_cache.sql
+++ b/synapse/storage/data_stores/main/schema/delta/43/url_cache.sql
diff --git a/synapse/storage/schema/delta/43/user_share.sql b/synapse/storage/data_stores/main/schema/delta/43/user_share.sql
index ee7062abe4..ee7062abe4 100644
--- a/synapse/storage/schema/delta/43/user_share.sql
+++ b/synapse/storage/data_stores/main/schema/delta/43/user_share.sql
diff --git a/synapse/storage/schema/delta/44/expire_url_cache.sql b/synapse/storage/data_stores/main/schema/delta/44/expire_url_cache.sql
index b12f9b2ebf..b12f9b2ebf 100644
--- a/synapse/storage/schema/delta/44/expire_url_cache.sql
+++ b/synapse/storage/data_stores/main/schema/delta/44/expire_url_cache.sql
diff --git a/synapse/storage/schema/delta/45/group_server.sql b/synapse/storage/data_stores/main/schema/delta/45/group_server.sql
index b2333848a0..b2333848a0 100644
--- a/synapse/storage/schema/delta/45/group_server.sql
+++ b/synapse/storage/data_stores/main/schema/delta/45/group_server.sql
diff --git a/synapse/storage/schema/delta/45/profile_cache.sql b/synapse/storage/data_stores/main/schema/delta/45/profile_cache.sql
index e5ddc84df0..e5ddc84df0 100644
--- a/synapse/storage/schema/delta/45/profile_cache.sql
+++ b/synapse/storage/data_stores/main/schema/delta/45/profile_cache.sql
diff --git a/synapse/storage/schema/delta/46/drop_refresh_tokens.sql b/synapse/storage/data_stores/main/schema/delta/46/drop_refresh_tokens.sql
index 68c48a89a9..68c48a89a9 100644
--- a/synapse/storage/schema/delta/46/drop_refresh_tokens.sql
+++ b/synapse/storage/data_stores/main/schema/delta/46/drop_refresh_tokens.sql
diff --git a/synapse/storage/schema/delta/46/drop_unique_deleted_pushers.sql b/synapse/storage/data_stores/main/schema/delta/46/drop_unique_deleted_pushers.sql
index bb307889c1..bb307889c1 100644
--- a/synapse/storage/schema/delta/46/drop_unique_deleted_pushers.sql
+++ b/synapse/storage/data_stores/main/schema/delta/46/drop_unique_deleted_pushers.sql
diff --git a/synapse/storage/schema/delta/46/group_server.sql b/synapse/storage/data_stores/main/schema/delta/46/group_server.sql
index 097679bc9a..097679bc9a 100644
--- a/synapse/storage/schema/delta/46/group_server.sql
+++ b/synapse/storage/data_stores/main/schema/delta/46/group_server.sql
diff --git a/synapse/storage/schema/delta/46/local_media_repository_url_idx.sql b/synapse/storage/data_stores/main/schema/delta/46/local_media_repository_url_idx.sql
index bbfc7f5d1a..bbfc7f5d1a 100644
--- a/synapse/storage/schema/delta/46/local_media_repository_url_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/46/local_media_repository_url_idx.sql
diff --git a/synapse/storage/schema/delta/46/user_dir_null_room_ids.sql b/synapse/storage/data_stores/main/schema/delta/46/user_dir_null_room_ids.sql
index cb0d5a2576..cb0d5a2576 100644
--- a/synapse/storage/schema/delta/46/user_dir_null_room_ids.sql
+++ b/synapse/storage/data_stores/main/schema/delta/46/user_dir_null_room_ids.sql
diff --git a/synapse/storage/schema/delta/46/user_dir_typos.sql b/synapse/storage/data_stores/main/schema/delta/46/user_dir_typos.sql
index d9505f8da1..d9505f8da1 100644
--- a/synapse/storage/schema/delta/46/user_dir_typos.sql
+++ b/synapse/storage/data_stores/main/schema/delta/46/user_dir_typos.sql
diff --git a/synapse/storage/schema/delta/47/last_access_media.sql b/synapse/storage/data_stores/main/schema/delta/47/last_access_media.sql
index f505fb22b5..f505fb22b5 100644
--- a/synapse/storage/schema/delta/47/last_access_media.sql
+++ b/synapse/storage/data_stores/main/schema/delta/47/last_access_media.sql
diff --git a/synapse/storage/schema/delta/47/postgres_fts_gin.sql b/synapse/storage/data_stores/main/schema/delta/47/postgres_fts_gin.sql
index 31d7a817eb..31d7a817eb 100644
--- a/synapse/storage/schema/delta/47/postgres_fts_gin.sql
+++ b/synapse/storage/data_stores/main/schema/delta/47/postgres_fts_gin.sql
diff --git a/synapse/storage/schema/delta/47/push_actions_staging.sql b/synapse/storage/data_stores/main/schema/delta/47/push_actions_staging.sql
index edccf4a96f..edccf4a96f 100644
--- a/synapse/storage/schema/delta/47/push_actions_staging.sql
+++ b/synapse/storage/data_stores/main/schema/delta/47/push_actions_staging.sql
diff --git a/synapse/storage/schema/delta/47/state_group_seq.py b/synapse/storage/data_stores/main/schema/delta/47/state_group_seq.py
index 9fd1ccf6f7..9fd1ccf6f7 100644
--- a/synapse/storage/schema/delta/47/state_group_seq.py
+++ b/synapse/storage/data_stores/main/schema/delta/47/state_group_seq.py
diff --git a/synapse/storage/schema/delta/48/add_user_consent.sql b/synapse/storage/data_stores/main/schema/delta/48/add_user_consent.sql
index 5237491506..5237491506 100644
--- a/synapse/storage/schema/delta/48/add_user_consent.sql
+++ b/synapse/storage/data_stores/main/schema/delta/48/add_user_consent.sql
diff --git a/synapse/storage/schema/delta/48/add_user_ips_last_seen_index.sql b/synapse/storage/data_stores/main/schema/delta/48/add_user_ips_last_seen_index.sql
index 9248b0b24a..9248b0b24a 100644
--- a/synapse/storage/schema/delta/48/add_user_ips_last_seen_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/48/add_user_ips_last_seen_index.sql
diff --git a/synapse/storage/schema/delta/48/deactivated_users.sql b/synapse/storage/data_stores/main/schema/delta/48/deactivated_users.sql
index e9013a6969..e9013a6969 100644
--- a/synapse/storage/schema/delta/48/deactivated_users.sql
+++ b/synapse/storage/data_stores/main/schema/delta/48/deactivated_users.sql
diff --git a/synapse/storage/schema/delta/48/group_unique_indexes.py b/synapse/storage/data_stores/main/schema/delta/48/group_unique_indexes.py
index 49f5f2c003..49f5f2c003 100644
--- a/synapse/storage/schema/delta/48/group_unique_indexes.py
+++ b/synapse/storage/data_stores/main/schema/delta/48/group_unique_indexes.py
diff --git a/synapse/storage/schema/delta/48/groups_joinable.sql b/synapse/storage/data_stores/main/schema/delta/48/groups_joinable.sql
index ce26eaf0c9..ce26eaf0c9 100644
--- a/synapse/storage/schema/delta/48/groups_joinable.sql
+++ b/synapse/storage/data_stores/main/schema/delta/48/groups_joinable.sql
diff --git a/synapse/storage/schema/delta/49/add_user_consent_server_notice_sent.sql b/synapse/storage/data_stores/main/schema/delta/49/add_user_consent_server_notice_sent.sql
index 14dcf18d73..14dcf18d73 100644
--- a/synapse/storage/schema/delta/49/add_user_consent_server_notice_sent.sql
+++ b/synapse/storage/data_stores/main/schema/delta/49/add_user_consent_server_notice_sent.sql
diff --git a/synapse/storage/schema/delta/49/add_user_daily_visits.sql b/synapse/storage/data_stores/main/schema/delta/49/add_user_daily_visits.sql
index 3dd478196f..3dd478196f 100644
--- a/synapse/storage/schema/delta/49/add_user_daily_visits.sql
+++ b/synapse/storage/data_stores/main/schema/delta/49/add_user_daily_visits.sql
diff --git a/synapse/storage/schema/delta/49/add_user_ips_last_seen_only_index.sql b/synapse/storage/data_stores/main/schema/delta/49/add_user_ips_last_seen_only_index.sql
index 3a4ed59b5b..3a4ed59b5b 100644
--- a/synapse/storage/schema/delta/49/add_user_ips_last_seen_only_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/49/add_user_ips_last_seen_only_index.sql
diff --git a/synapse/storage/schema/delta/50/add_creation_ts_users_index.sql b/synapse/storage/data_stores/main/schema/delta/50/add_creation_ts_users_index.sql
index c93ae47532..c93ae47532 100644
--- a/synapse/storage/schema/delta/50/add_creation_ts_users_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/50/add_creation_ts_users_index.sql
diff --git a/synapse/storage/schema/delta/50/erasure_store.sql b/synapse/storage/data_stores/main/schema/delta/50/erasure_store.sql
index 5d8641a9ab..5d8641a9ab 100644
--- a/synapse/storage/schema/delta/50/erasure_store.sql
+++ b/synapse/storage/data_stores/main/schema/delta/50/erasure_store.sql
diff --git a/synapse/storage/schema/delta/50/make_event_content_nullable.py b/synapse/storage/data_stores/main/schema/delta/50/make_event_content_nullable.py
index b1684a8441..b1684a8441 100644
--- a/synapse/storage/schema/delta/50/make_event_content_nullable.py
+++ b/synapse/storage/data_stores/main/schema/delta/50/make_event_content_nullable.py
diff --git a/synapse/storage/schema/delta/51/e2e_room_keys.sql b/synapse/storage/data_stores/main/schema/delta/51/e2e_room_keys.sql
index c0e66a697d..c0e66a697d 100644
--- a/synapse/storage/schema/delta/51/e2e_room_keys.sql
+++ b/synapse/storage/data_stores/main/schema/delta/51/e2e_room_keys.sql
diff --git a/synapse/storage/schema/delta/51/monthly_active_users.sql b/synapse/storage/data_stores/main/schema/delta/51/monthly_active_users.sql
index c9d537d5a3..c9d537d5a3 100644
--- a/synapse/storage/schema/delta/51/monthly_active_users.sql
+++ b/synapse/storage/data_stores/main/schema/delta/51/monthly_active_users.sql
diff --git a/synapse/storage/schema/delta/52/add_event_to_state_group_index.sql b/synapse/storage/data_stores/main/schema/delta/52/add_event_to_state_group_index.sql
index 91e03d13e1..91e03d13e1 100644
--- a/synapse/storage/schema/delta/52/add_event_to_state_group_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/52/add_event_to_state_group_index.sql
diff --git a/synapse/storage/schema/delta/52/device_list_streams_unique_idx.sql b/synapse/storage/data_stores/main/schema/delta/52/device_list_streams_unique_idx.sql
index bfa49e6f92..bfa49e6f92 100644
--- a/synapse/storage/schema/delta/52/device_list_streams_unique_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/52/device_list_streams_unique_idx.sql
diff --git a/synapse/storage/schema/delta/52/e2e_room_keys.sql b/synapse/storage/data_stores/main/schema/delta/52/e2e_room_keys.sql
index db687cccae..db687cccae 100644
--- a/synapse/storage/schema/delta/52/e2e_room_keys.sql
+++ b/synapse/storage/data_stores/main/schema/delta/52/e2e_room_keys.sql
diff --git a/synapse/storage/schema/delta/53/add_user_type_to_users.sql b/synapse/storage/data_stores/main/schema/delta/53/add_user_type_to_users.sql
index 88ec2f83e5..88ec2f83e5 100644
--- a/synapse/storage/schema/delta/53/add_user_type_to_users.sql
+++ b/synapse/storage/data_stores/main/schema/delta/53/add_user_type_to_users.sql
diff --git a/synapse/storage/schema/delta/53/drop_sent_transactions.sql b/synapse/storage/data_stores/main/schema/delta/53/drop_sent_transactions.sql
index e372f5a44a..e372f5a44a 100644
--- a/synapse/storage/schema/delta/53/drop_sent_transactions.sql
+++ b/synapse/storage/data_stores/main/schema/delta/53/drop_sent_transactions.sql
diff --git a/synapse/storage/schema/delta/53/event_format_version.sql b/synapse/storage/data_stores/main/schema/delta/53/event_format_version.sql
index 1d977c2834..1d977c2834 100644
--- a/synapse/storage/schema/delta/53/event_format_version.sql
+++ b/synapse/storage/data_stores/main/schema/delta/53/event_format_version.sql
diff --git a/synapse/storage/schema/delta/53/user_dir_populate.sql b/synapse/storage/data_stores/main/schema/delta/53/user_dir_populate.sql
index ffcc896b58..ffcc896b58 100644
--- a/synapse/storage/schema/delta/53/user_dir_populate.sql
+++ b/synapse/storage/data_stores/main/schema/delta/53/user_dir_populate.sql
diff --git a/synapse/storage/schema/delta/53/user_ips_index.sql b/synapse/storage/data_stores/main/schema/delta/53/user_ips_index.sql
index b812c5794f..b812c5794f 100644
--- a/synapse/storage/schema/delta/53/user_ips_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/53/user_ips_index.sql
diff --git a/synapse/storage/schema/delta/53/user_share.sql b/synapse/storage/data_stores/main/schema/delta/53/user_share.sql
index 5831b1a6f8..5831b1a6f8 100644
--- a/synapse/storage/schema/delta/53/user_share.sql
+++ b/synapse/storage/data_stores/main/schema/delta/53/user_share.sql
diff --git a/synapse/storage/schema/delta/53/user_threepid_id.sql b/synapse/storage/data_stores/main/schema/delta/53/user_threepid_id.sql
index 80c2c573b6..80c2c573b6 100644
--- a/synapse/storage/schema/delta/53/user_threepid_id.sql
+++ b/synapse/storage/data_stores/main/schema/delta/53/user_threepid_id.sql
diff --git a/synapse/storage/schema/delta/53/users_in_public_rooms.sql b/synapse/storage/data_stores/main/schema/delta/53/users_in_public_rooms.sql
index f7827ca6d2..f7827ca6d2 100644
--- a/synapse/storage/schema/delta/53/users_in_public_rooms.sql
+++ b/synapse/storage/data_stores/main/schema/delta/53/users_in_public_rooms.sql
diff --git a/synapse/storage/schema/delta/54/account_validity_with_renewal.sql b/synapse/storage/data_stores/main/schema/delta/54/account_validity_with_renewal.sql
index 0adb2ad55e..0adb2ad55e 100644
--- a/synapse/storage/schema/delta/54/account_validity_with_renewal.sql
+++ b/synapse/storage/data_stores/main/schema/delta/54/account_validity_with_renewal.sql
diff --git a/synapse/storage/schema/delta/54/add_validity_to_server_keys.sql b/synapse/storage/data_stores/main/schema/delta/54/add_validity_to_server_keys.sql
index c01aa9d2d9..c01aa9d2d9 100644
--- a/synapse/storage/schema/delta/54/add_validity_to_server_keys.sql
+++ b/synapse/storage/data_stores/main/schema/delta/54/add_validity_to_server_keys.sql
diff --git a/synapse/storage/schema/delta/54/delete_forward_extremities.sql b/synapse/storage/data_stores/main/schema/delta/54/delete_forward_extremities.sql
index b062ec840c..b062ec840c 100644
--- a/synapse/storage/schema/delta/54/delete_forward_extremities.sql
+++ b/synapse/storage/data_stores/main/schema/delta/54/delete_forward_extremities.sql
diff --git a/synapse/storage/schema/delta/54/drop_legacy_tables.sql b/synapse/storage/data_stores/main/schema/delta/54/drop_legacy_tables.sql
index dbbe682697..dbbe682697 100644
--- a/synapse/storage/schema/delta/54/drop_legacy_tables.sql
+++ b/synapse/storage/data_stores/main/schema/delta/54/drop_legacy_tables.sql
diff --git a/synapse/storage/schema/delta/54/drop_presence_list.sql b/synapse/storage/data_stores/main/schema/delta/54/drop_presence_list.sql
index e6ee70c623..e6ee70c623 100644
--- a/synapse/storage/schema/delta/54/drop_presence_list.sql
+++ b/synapse/storage/data_stores/main/schema/delta/54/drop_presence_list.sql
diff --git a/synapse/storage/schema/delta/54/relations.sql b/synapse/storage/data_stores/main/schema/delta/54/relations.sql
index 134862b870..134862b870 100644
--- a/synapse/storage/schema/delta/54/relations.sql
+++ b/synapse/storage/data_stores/main/schema/delta/54/relations.sql
diff --git a/synapse/storage/schema/delta/54/stats.sql b/synapse/storage/data_stores/main/schema/delta/54/stats.sql
index 652e58308e..652e58308e 100644
--- a/synapse/storage/schema/delta/54/stats.sql
+++ b/synapse/storage/data_stores/main/schema/delta/54/stats.sql
diff --git a/synapse/storage/schema/delta/54/stats2.sql b/synapse/storage/data_stores/main/schema/delta/54/stats2.sql
index 3b2d48447f..3b2d48447f 100644
--- a/synapse/storage/schema/delta/54/stats2.sql
+++ b/synapse/storage/data_stores/main/schema/delta/54/stats2.sql
diff --git a/synapse/storage/schema/delta/55/access_token_expiry.sql b/synapse/storage/data_stores/main/schema/delta/55/access_token_expiry.sql
index 4590604bfd..4590604bfd 100644
--- a/synapse/storage/schema/delta/55/access_token_expiry.sql
+++ b/synapse/storage/data_stores/main/schema/delta/55/access_token_expiry.sql
diff --git a/synapse/storage/schema/delta/55/track_threepid_validations.sql b/synapse/storage/data_stores/main/schema/delta/55/track_threepid_validations.sql
index a8eced2e0a..a8eced2e0a 100644
--- a/synapse/storage/schema/delta/55/track_threepid_validations.sql
+++ b/synapse/storage/data_stores/main/schema/delta/55/track_threepid_validations.sql
diff --git a/synapse/storage/schema/delta/55/users_alter_deactivated.sql b/synapse/storage/data_stores/main/schema/delta/55/users_alter_deactivated.sql
index dabdde489b..dabdde489b 100644
--- a/synapse/storage/schema/delta/55/users_alter_deactivated.sql
+++ b/synapse/storage/data_stores/main/schema/delta/55/users_alter_deactivated.sql
diff --git a/synapse/storage/schema/delta/56/add_spans_to_device_lists.sql b/synapse/storage/data_stores/main/schema/delta/56/add_spans_to_device_lists.sql
index 41807eb1e7..41807eb1e7 100644
--- a/synapse/storage/schema/delta/56/add_spans_to_device_lists.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/add_spans_to_device_lists.sql
diff --git a/synapse/storage/schema/delta/56/current_state_events_membership.sql b/synapse/storage/data_stores/main/schema/delta/56/current_state_events_membership.sql
index 473018676f..473018676f 100644
--- a/synapse/storage/schema/delta/56/current_state_events_membership.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/current_state_events_membership.sql
diff --git a/synapse/storage/schema/delta/56/current_state_events_membership_mk2.sql b/synapse/storage/data_stores/main/schema/delta/56/current_state_events_membership_mk2.sql
index 3133d42d4a..3133d42d4a 100644
--- a/synapse/storage/schema/delta/56/current_state_events_membership_mk2.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/current_state_events_membership_mk2.sql
diff --git a/synapse/storage/schema/delta/56/destinations_failure_ts.sql b/synapse/storage/data_stores/main/schema/delta/56/destinations_failure_ts.sql
index f00889290b..f00889290b 100644
--- a/synapse/storage/schema/delta/56/destinations_failure_ts.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/destinations_failure_ts.sql
diff --git a/synapse/storage/schema/delta/56/destinations_retry_interval_type.sql.postgres b/synapse/storage/data_stores/main/schema/delta/56/destinations_retry_interval_type.sql.postgres
index b9bbb18a91..b9bbb18a91 100644
--- a/synapse/storage/schema/delta/56/destinations_retry_interval_type.sql.postgres
+++ b/synapse/storage/data_stores/main/schema/delta/56/destinations_retry_interval_type.sql.postgres
diff --git a/synapse/storage/schema/delta/56/devices_last_seen.sql b/synapse/storage/data_stores/main/schema/delta/56/devices_last_seen.sql
index dfa902d0ba..dfa902d0ba 100644
--- a/synapse/storage/schema/delta/56/devices_last_seen.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/devices_last_seen.sql
diff --git a/synapse/storage/schema/delta/56/drop_unused_event_tables.sql b/synapse/storage/data_stores/main/schema/delta/56/drop_unused_event_tables.sql
index 9f09922c67..9f09922c67 100644
--- a/synapse/storage/schema/delta/56/drop_unused_event_tables.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/drop_unused_event_tables.sql
diff --git a/synapse/storage/schema/delta/56/fix_room_keys_index.sql b/synapse/storage/data_stores/main/schema/delta/56/fix_room_keys_index.sql
index 014cb3b538..014cb3b538 100644
--- a/synapse/storage/schema/delta/56/fix_room_keys_index.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/fix_room_keys_index.sql
diff --git a/synapse/storage/schema/delta/56/hidden_devices.sql b/synapse/storage/data_stores/main/schema/delta/56/hidden_devices.sql
index 67f8b20297..67f8b20297 100644
--- a/synapse/storage/schema/delta/56/hidden_devices.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/hidden_devices.sql
diff --git a/synapse/storage/schema/delta/56/public_room_list_idx.sql b/synapse/storage/data_stores/main/schema/delta/56/public_room_list_idx.sql
index 7be31ffebb..7be31ffebb 100644
--- a/synapse/storage/schema/delta/56/public_room_list_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/public_room_list_idx.sql
diff --git a/synapse/storage/schema/delta/56/redaction_censor.sql b/synapse/storage/data_stores/main/schema/delta/56/redaction_censor.sql
index fe51b02309..fe51b02309 100644
--- a/synapse/storage/schema/delta/56/redaction_censor.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/redaction_censor.sql
diff --git a/synapse/storage/schema/delta/56/redaction_censor2.sql b/synapse/storage/data_stores/main/schema/delta/56/redaction_censor2.sql
index 77a5eca499..77a5eca499 100644
--- a/synapse/storage/schema/delta/56/redaction_censor2.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/redaction_censor2.sql
diff --git a/synapse/storage/schema/delta/56/redaction_censor3_fix_update.sql.postgres b/synapse/storage/data_stores/main/schema/delta/56/redaction_censor3_fix_update.sql.postgres
index 67471f3ef5..67471f3ef5 100644
--- a/synapse/storage/schema/delta/56/redaction_censor3_fix_update.sql.postgres
+++ b/synapse/storage/data_stores/main/schema/delta/56/redaction_censor3_fix_update.sql.postgres
diff --git a/synapse/storage/schema/delta/56/room_membership_idx.sql b/synapse/storage/data_stores/main/schema/delta/56/room_membership_idx.sql
index 92ab1f5e65..92ab1f5e65 100644
--- a/synapse/storage/schema/delta/56/room_membership_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/room_membership_idx.sql
diff --git a/synapse/storage/schema/delta/56/signing_keys.sql b/synapse/storage/data_stores/main/schema/delta/56/signing_keys.sql
index 27a96123e3..27a96123e3 100644
--- a/synapse/storage/schema/delta/56/signing_keys.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/signing_keys.sql
diff --git a/synapse/storage/schema/delta/56/stats_separated.sql b/synapse/storage/data_stores/main/schema/delta/56/stats_separated.sql
index 163529c071..163529c071 100644
--- a/synapse/storage/schema/delta/56/stats_separated.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/stats_separated.sql
diff --git a/synapse/storage/schema/delta/56/unique_user_filter_index.py b/synapse/storage/data_stores/main/schema/delta/56/unique_user_filter_index.py
index 1de8b54961..1de8b54961 100644
--- a/synapse/storage/schema/delta/56/unique_user_filter_index.py
+++ b/synapse/storage/data_stores/main/schema/delta/56/unique_user_filter_index.py
diff --git a/synapse/storage/schema/delta/56/user_external_ids.sql b/synapse/storage/data_stores/main/schema/delta/56/user_external_ids.sql
index 91390c4527..91390c4527 100644
--- a/synapse/storage/schema/delta/56/user_external_ids.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/user_external_ids.sql
diff --git a/synapse/storage/schema/delta/56/users_in_public_rooms_idx.sql b/synapse/storage/data_stores/main/schema/delta/56/users_in_public_rooms_idx.sql
index 149f8be8b6..149f8be8b6 100644
--- a/synapse/storage/schema/delta/56/users_in_public_rooms_idx.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/users_in_public_rooms_idx.sql
diff --git a/synapse/storage/schema/full_schemas/16/application_services.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/application_services.sql
index 883fcd10b2..883fcd10b2 100644
--- a/synapse/storage/schema/full_schemas/16/application_services.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/application_services.sql
diff --git a/synapse/storage/schema/full_schemas/16/event_edges.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/event_edges.sql
index 10ce2aa7a0..10ce2aa7a0 100644
--- a/synapse/storage/schema/full_schemas/16/event_edges.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/event_edges.sql
diff --git a/synapse/storage/schema/full_schemas/16/event_signatures.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/event_signatures.sql
index 95826da431..95826da431 100644
--- a/synapse/storage/schema/full_schemas/16/event_signatures.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/event_signatures.sql
diff --git a/synapse/storage/schema/full_schemas/16/im.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/im.sql
index a1a2aa8e5b..a1a2aa8e5b 100644
--- a/synapse/storage/schema/full_schemas/16/im.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/im.sql
diff --git a/synapse/storage/schema/full_schemas/16/keys.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/keys.sql
index 11cdffdbb3..11cdffdbb3 100644
--- a/synapse/storage/schema/full_schemas/16/keys.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/keys.sql
diff --git a/synapse/storage/schema/full_schemas/16/media_repository.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/media_repository.sql
index 8f3759bb2a..8f3759bb2a 100644
--- a/synapse/storage/schema/full_schemas/16/media_repository.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/media_repository.sql
diff --git a/synapse/storage/schema/full_schemas/16/presence.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/presence.sql
index 01d2d8f833..01d2d8f833 100644
--- a/synapse/storage/schema/full_schemas/16/presence.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/presence.sql
diff --git a/synapse/storage/schema/full_schemas/16/profiles.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/profiles.sql
index c04f4747d9..c04f4747d9 100644
--- a/synapse/storage/schema/full_schemas/16/profiles.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/profiles.sql
diff --git a/synapse/storage/schema/full_schemas/16/push.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/push.sql
index e44465cf45..e44465cf45 100644
--- a/synapse/storage/schema/full_schemas/16/push.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/push.sql
diff --git a/synapse/storage/schema/full_schemas/16/redactions.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/redactions.sql
index 318f0d9aa5..318f0d9aa5 100644
--- a/synapse/storage/schema/full_schemas/16/redactions.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/redactions.sql
diff --git a/synapse/storage/schema/full_schemas/16/room_aliases.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/room_aliases.sql
index d47da3b12f..d47da3b12f 100644
--- a/synapse/storage/schema/full_schemas/16/room_aliases.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/room_aliases.sql
diff --git a/synapse/storage/schema/full_schemas/16/state.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/state.sql
index 96391a8f0e..96391a8f0e 100644
--- a/synapse/storage/schema/full_schemas/16/state.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/state.sql
diff --git a/synapse/storage/schema/full_schemas/16/transactions.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/transactions.sql
index 17e67bedac..17e67bedac 100644
--- a/synapse/storage/schema/full_schemas/16/transactions.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/transactions.sql
diff --git a/synapse/storage/schema/full_schemas/16/users.sql b/synapse/storage/data_stores/main/schema/full_schemas/16/users.sql
index f013aa8b18..f013aa8b18 100644
--- a/synapse/storage/schema/full_schemas/16/users.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/16/users.sql
diff --git a/synapse/storage/schema/full_schemas/54/full.sql.postgres b/synapse/storage/data_stores/main/schema/full_schemas/54/full.sql.postgres
index 098434356f..4ad2929f32 100644
--- a/synapse/storage/schema/full_schemas/54/full.sql.postgres
+++ b/synapse/storage/data_stores/main/schema/full_schemas/54/full.sql.postgres
@@ -70,15 +70,6 @@ CREATE TABLE appservice_stream_position (
 );
 
 
-
-CREATE TABLE background_updates (
-    update_name text NOT NULL,
-    progress_json text NOT NULL,
-    depends_on text
-);
-
-
-
 CREATE TABLE blocked_rooms (
     room_id text NOT NULL,
     user_id text NOT NULL
@@ -1202,11 +1193,6 @@ ALTER TABLE ONLY appservice_stream_position
 
 
 
-ALTER TABLE ONLY background_updates
-    ADD CONSTRAINT background_updates_uniqueness UNIQUE (update_name);
-
-
-
 ALTER TABLE ONLY current_state_events
     ADD CONSTRAINT current_state_events_event_id_key UNIQUE (event_id);
 
@@ -2047,6 +2033,3 @@ CREATE INDEX users_who_share_private_rooms_r_idx ON users_who_share_private_room
 
 
 CREATE UNIQUE INDEX users_who_share_private_rooms_u_idx ON users_who_share_private_rooms USING btree (user_id, other_user_id, room_id);
-
-
-
diff --git a/synapse/storage/schema/full_schemas/54/full.sql.sqlite b/synapse/storage/data_stores/main/schema/full_schemas/54/full.sql.sqlite
index be9295e4c9..bad33291e7 100644
--- a/synapse/storage/schema/full_schemas/54/full.sql.sqlite
+++ b/synapse/storage/data_stores/main/schema/full_schemas/54/full.sql.sqlite
@@ -67,7 +67,6 @@ CREATE INDEX receipts_linearized_id ON receipts_linearized( stream_id );
 CREATE INDEX receipts_linearized_room_stream ON receipts_linearized( room_id, stream_id );
 CREATE TABLE IF NOT EXISTS "user_threepids" ( user_id TEXT NOT NULL, medium TEXT NOT NULL, address TEXT NOT NULL, validated_at BIGINT NOT NULL, added_at BIGINT NOT NULL, CONSTRAINT medium_address UNIQUE (medium, address) );
 CREATE INDEX user_threepids_user_id ON user_threepids(user_id);
-CREATE TABLE background_updates( update_name TEXT NOT NULL, progress_json TEXT NOT NULL, depends_on TEXT, CONSTRAINT background_updates_uniqueness UNIQUE (update_name) );
 CREATE VIRTUAL TABLE event_search USING fts4 ( event_id, room_id, sender, key, value )
 /* event_search(event_id,room_id,sender,"key",value) */;
 CREATE TABLE IF NOT EXISTS 'event_search_content'(docid INTEGER PRIMARY KEY, 'c0event_id', 'c1room_id', 'c2sender', 'c3key', 'c4value');
diff --git a/synapse/storage/schema/full_schemas/54/stream_positions.sql b/synapse/storage/data_stores/main/schema/full_schemas/54/stream_positions.sql
index c265fd20e2..c265fd20e2 100644
--- a/synapse/storage/schema/full_schemas/54/stream_positions.sql
+++ b/synapse/storage/data_stores/main/schema/full_schemas/54/stream_positions.sql
diff --git a/synapse/storage/schema/full_schemas/README.txt b/synapse/storage/data_stores/main/schema/full_schemas/README.txt
index d3f6401344..d3f6401344 100644
--- a/synapse/storage/schema/full_schemas/README.txt
+++ b/synapse/storage/data_stores/main/schema/full_schemas/README.txt
diff --git a/synapse/storage/search.py b/synapse/storage/data_stores/main/search.py
index 7695bf09fc..0e08497452 100644
--- a/synapse/storage/search.py
+++ b/synapse/storage/data_stores/main/search.py
@@ -25,10 +25,9 @@ from twisted.internet import defer
 
 from synapse.api.errors import SynapseError
 from synapse.storage._base import make_in_list_sql_clause
+from synapse.storage.background_updates import BackgroundUpdateStore
 from synapse.storage.engines import PostgresEngine, Sqlite3Engine
 
-from .background_updates import BackgroundUpdateStore
-
 logger = logging.getLogger(__name__)
 
 SearchEntry = namedtuple(
diff --git a/synapse/storage/signatures.py b/synapse/storage/data_stores/main/signatures.py
index fb83218f90..556191b76f 100644
--- a/synapse/storage/signatures.py
+++ b/synapse/storage/data_stores/main/signatures.py
@@ -20,10 +20,9 @@ from unpaddedbase64 import encode_base64
 from twisted.internet import defer
 
 from synapse.crypto.event_signing import compute_event_reference_hash
+from synapse.storage._base import SQLBaseStore
 from synapse.util.caches.descriptors import cached, cachedList
 
-from ._base import SQLBaseStore
-
 # py2 sqlite has buffer hardcoded as only binary type, so we must use it,
 # despite being deprecated and removed in favor of memoryview
 if six.PY2:
diff --git a/synapse/storage/data_stores/main/state.py b/synapse/storage/data_stores/main/state.py
new file mode 100644
index 0000000000..d54442e5fa
--- /dev/null
+++ b/synapse/storage/data_stores/main/state.py
@@ -0,0 +1,1244 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from collections import namedtuple
+
+from six import iteritems, itervalues
+from six.moves import range
+
+from twisted.internet import defer
+
+from synapse.api.constants import EventTypes
+from synapse.api.errors import NotFoundError
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.background_updates import BackgroundUpdateStore
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
+from synapse.storage.engines import PostgresEngine
+from synapse.storage.state import StateFilter
+from synapse.util.caches import get_cache_factor_for, intern_string
+from synapse.util.caches.descriptors import cached, cachedList
+from synapse.util.caches.dictionary_cache import DictionaryCache
+from synapse.util.stringutils import to_ascii
+
+logger = logging.getLogger(__name__)
+
+
+MAX_STATE_DELTA_HOPS = 100
+
+
+class _GetStateGroupDelta(
+    namedtuple("_GetStateGroupDelta", ("prev_group", "delta_ids"))
+):
+    """Return type of get_state_group_delta that implements __len__, which lets
+    us use the itrable flag when caching
+    """
+
+    __slots__ = []
+
+    def __len__(self):
+        return len(self.delta_ids) if self.delta_ids else 0
+
+
+class StateGroupBackgroundUpdateStore(SQLBaseStore):
+    """Defines functions related to state groups needed to run the state backgroud
+    updates.
+    """
+
+    def _count_state_group_hops_txn(self, txn, state_group):
+        """Given a state group, count how many hops there are in the tree.
+
+        This is used to ensure the delta chains don't get too long.
+        """
+        if isinstance(self.database_engine, PostgresEngine):
+            sql = """
+                WITH RECURSIVE state(state_group) AS (
+                    VALUES(?::bigint)
+                    UNION ALL
+                    SELECT prev_state_group FROM state_group_edges e, state s
+                    WHERE s.state_group = e.state_group
+                )
+                SELECT count(*) FROM state;
+            """
+
+            txn.execute(sql, (state_group,))
+            row = txn.fetchone()
+            if row and row[0]:
+                return row[0]
+            else:
+                return 0
+        else:
+            # We don't use WITH RECURSIVE on sqlite3 as there are distributions
+            # that ship with an sqlite3 version that doesn't support it (e.g. wheezy)
+            next_group = state_group
+            count = 0
+
+            while next_group:
+                next_group = self._simple_select_one_onecol_txn(
+                    txn,
+                    table="state_group_edges",
+                    keyvalues={"state_group": next_group},
+                    retcol="prev_state_group",
+                    allow_none=True,
+                )
+                if next_group:
+                    count += 1
+
+            return count
+
+    def _get_state_groups_from_groups_txn(
+        self, txn, groups, state_filter=StateFilter.all()
+    ):
+        results = {group: {} for group in groups}
+
+        where_clause, where_args = state_filter.make_sql_filter_clause()
+
+        # Unless the filter clause is empty, we're going to append it after an
+        # existing where clause
+        if where_clause:
+            where_clause = " AND (%s)" % (where_clause,)
+
+        if isinstance(self.database_engine, PostgresEngine):
+            # Temporarily disable sequential scans in this transaction. This is
+            # a temporary hack until we can add the right indices in
+            txn.execute("SET LOCAL enable_seqscan=off")
+
+            # The below query walks the state_group tree so that the "state"
+            # table includes all state_groups in the tree. It then joins
+            # against `state_groups_state` to fetch the latest state.
+            # It assumes that previous state groups are always numerically
+            # lesser.
+            # The PARTITION is used to get the event_id in the greatest state
+            # group for the given type, state_key.
+            # This may return multiple rows per (type, state_key), but last_value
+            # should be the same.
+            sql = """
+                WITH RECURSIVE state(state_group) AS (
+                    VALUES(?::bigint)
+                    UNION ALL
+                    SELECT prev_state_group FROM state_group_edges e, state s
+                    WHERE s.state_group = e.state_group
+                )
+                SELECT DISTINCT type, state_key, last_value(event_id) OVER (
+                    PARTITION BY type, state_key ORDER BY state_group ASC
+                    ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
+                ) AS event_id FROM state_groups_state
+                WHERE state_group IN (
+                    SELECT state_group FROM state
+                )
+            """
+
+            for group in groups:
+                args = [group]
+                args.extend(where_args)
+
+                txn.execute(sql + where_clause, args)
+                for row in txn:
+                    typ, state_key, event_id = row
+                    key = (typ, state_key)
+                    results[group][key] = event_id
+        else:
+            max_entries_returned = state_filter.max_entries_returned()
+
+            # We don't use WITH RECURSIVE on sqlite3 as there are distributions
+            # that ship with an sqlite3 version that doesn't support it (e.g. wheezy)
+            for group in groups:
+                next_group = group
+
+                while next_group:
+                    # We did this before by getting the list of group ids, and
+                    # then passing that list to sqlite to get latest event for
+                    # each (type, state_key). However, that was terribly slow
+                    # without the right indices (which we can't add until
+                    # after we finish deduping state, which requires this func)
+                    args = [next_group]
+                    args.extend(where_args)
+
+                    txn.execute(
+                        "SELECT type, state_key, event_id FROM state_groups_state"
+                        " WHERE state_group = ? " + where_clause,
+                        args,
+                    )
+                    results[group].update(
+                        ((typ, state_key), event_id)
+                        for typ, state_key, event_id in txn
+                        if (typ, state_key) not in results[group]
+                    )
+
+                    # If the number of entries in the (type,state_key)->event_id dict
+                    # matches the number of (type,state_keys) types we were searching
+                    # for, then we must have found them all, so no need to go walk
+                    # further down the tree... UNLESS our types filter contained
+                    # wildcards (i.e. Nones) in which case we have to do an exhaustive
+                    # search
+                    if (
+                        max_entries_returned is not None
+                        and len(results[group]) == max_entries_returned
+                    ):
+                        break
+
+                    next_group = self._simple_select_one_onecol_txn(
+                        txn,
+                        table="state_group_edges",
+                        keyvalues={"state_group": next_group},
+                        retcol="prev_state_group",
+                        allow_none=True,
+                    )
+
+        return results
+
+
+# this inherits from EventsWorkerStore because it calls self.get_events
+class StateGroupWorkerStore(
+    EventsWorkerStore, StateGroupBackgroundUpdateStore, SQLBaseStore
+):
+    """The parts of StateGroupStore that can be called from workers.
+    """
+
+    STATE_GROUP_DEDUPLICATION_UPDATE_NAME = "state_group_state_deduplication"
+    STATE_GROUP_INDEX_UPDATE_NAME = "state_group_state_type_index"
+    CURRENT_STATE_INDEX_UPDATE_NAME = "current_state_members_idx"
+
+    def __init__(self, db_conn, hs):
+        super(StateGroupWorkerStore, self).__init__(db_conn, hs)
+
+        # Originally the state store used a single DictionaryCache to cache the
+        # event IDs for the state types in a given state group to avoid hammering
+        # on the state_group* tables.
+        #
+        # The point of using a DictionaryCache is that it can cache a subset
+        # of the state events for a given state group (i.e. a subset of the keys for a
+        # given dict which is an entry in the cache for a given state group ID).
+        #
+        # However, this poses problems when performing complicated queries
+        # on the store - for instance: "give me all the state for this group, but
+        # limit members to this subset of users", as DictionaryCache's API isn't
+        # rich enough to say "please cache any of these fields, apart from this subset".
+        # This is problematic when lazy loading members, which requires this behaviour,
+        # as without it the cache has no choice but to speculatively load all
+        # state events for the group, which negates the efficiency being sought.
+        #
+        # Rather than overcomplicating DictionaryCache's API, we instead split the
+        # state_group_cache into two halves - one for tracking non-member events,
+        # and the other for tracking member_events.  This means that lazy loading
+        # queries can be made in a cache-friendly manner by querying both caches
+        # separately and then merging the result.  So for the example above, you
+        # would query the members cache for a specific subset of state keys
+        # (which DictionaryCache will handle efficiently and fine) and the non-members
+        # cache for all state (which DictionaryCache will similarly handle fine)
+        # and then just merge the results together.
+        #
+        # We size the non-members cache to be smaller than the members cache as the
+        # vast majority of state in Matrix (today) is member events.
+
+        self._state_group_cache = DictionaryCache(
+            "*stateGroupCache*",
+            # TODO: this hasn't been tuned yet
+            50000 * get_cache_factor_for("stateGroupCache"),
+        )
+        self._state_group_members_cache = DictionaryCache(
+            "*stateGroupMembersCache*",
+            500000 * get_cache_factor_for("stateGroupMembersCache"),
+        )
+
+    @defer.inlineCallbacks
+    def get_room_version(self, room_id):
+        """Get the room_version of a given room
+
+        Args:
+            room_id (str)
+
+        Returns:
+            Deferred[str]
+
+        Raises:
+            NotFoundError if the room is unknown
+        """
+        # for now we do this by looking at the create event. We may want to cache this
+        # more intelligently in future.
+
+        # Retrieve the room's create event
+        create_event = yield self.get_create_event_for_room(room_id)
+        return create_event.content.get("room_version", "1")
+
+    @defer.inlineCallbacks
+    def get_room_predecessor(self, room_id):
+        """Get the predecessor room of an upgraded room if one exists.
+        Otherwise return None.
+
+        Args:
+            room_id (str)
+
+        Returns:
+            Deferred[unicode|None]: predecessor room id
+
+        Raises:
+            NotFoundError if the room is unknown
+        """
+        # Retrieve the room's create event
+        create_event = yield self.get_create_event_for_room(room_id)
+
+        # Return predecessor if present
+        return create_event.content.get("predecessor", None)
+
+    @defer.inlineCallbacks
+    def get_create_event_for_room(self, room_id):
+        """Get the create state event for a room.
+
+        Args:
+            room_id (str)
+
+        Returns:
+            Deferred[EventBase]: The room creation event.
+
+        Raises:
+            NotFoundError if the room is unknown
+        """
+        state_ids = yield self.get_current_state_ids(room_id)
+        create_id = state_ids.get((EventTypes.Create, ""))
+
+        # If we can't find the create event, assume we've hit a dead end
+        if not create_id:
+            raise NotFoundError("Unknown room %s" % (room_id))
+
+        # Retrieve the room's create event and return
+        create_event = yield self.get_event(create_id)
+        return create_event
+
+    @cached(max_entries=100000, iterable=True)
+    def get_current_state_ids(self, room_id):
+        """Get the current state event ids for a room based on the
+        current_state_events table.
+
+        Args:
+            room_id (str)
+
+        Returns:
+            deferred: dict of (type, state_key) -> event_id
+        """
+
+        def _get_current_state_ids_txn(txn):
+            txn.execute(
+                """SELECT type, state_key, event_id FROM current_state_events
+                WHERE room_id = ?
+                """,
+                (room_id,),
+            )
+
+            return {
+                (intern_string(r[0]), intern_string(r[1])): to_ascii(r[2]) for r in txn
+            }
+
+        return self.runInteraction("get_current_state_ids", _get_current_state_ids_txn)
+
+    # FIXME: how should this be cached?
+    def get_filtered_current_state_ids(self, room_id, state_filter=StateFilter.all()):
+        """Get the current state event of a given type for a room based on the
+        current_state_events table.  This may not be as up-to-date as the result
+        of doing a fresh state resolution as per state_handler.get_current_state
+
+        Args:
+            room_id (str)
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            Deferred[dict[tuple[str, str], str]]: Map from type/state_key to
+            event ID.
+        """
+
+        where_clause, where_args = state_filter.make_sql_filter_clause()
+
+        if not where_clause:
+            # We delegate to the cached version
+            return self.get_current_state_ids(room_id)
+
+        def _get_filtered_current_state_ids_txn(txn):
+            results = {}
+            sql = """
+                SELECT type, state_key, event_id FROM current_state_events
+                WHERE room_id = ?
+            """
+
+            if where_clause:
+                sql += " AND (%s)" % (where_clause,)
+
+            args = [room_id]
+            args.extend(where_args)
+            txn.execute(sql, args)
+            for row in txn:
+                typ, state_key, event_id = row
+                key = (intern_string(typ), intern_string(state_key))
+                results[key] = event_id
+
+            return results
+
+        return self.runInteraction(
+            "get_filtered_current_state_ids", _get_filtered_current_state_ids_txn
+        )
+
+    @defer.inlineCallbacks
+    def get_canonical_alias_for_room(self, room_id):
+        """Get canonical alias for room, if any
+
+        Args:
+            room_id (str)
+
+        Returns:
+            Deferred[str|None]: The canonical alias, if any
+        """
+
+        state = yield self.get_filtered_current_state_ids(
+            room_id, StateFilter.from_types([(EventTypes.CanonicalAlias, "")])
+        )
+
+        event_id = state.get((EventTypes.CanonicalAlias, ""))
+        if not event_id:
+            return
+
+        event = yield self.get_event(event_id, allow_none=True)
+        if not event:
+            return
+
+        return event.content.get("canonical_alias")
+
+    @cached(max_entries=10000, iterable=True)
+    def get_state_group_delta(self, state_group):
+        """Given a state group try to return a previous group and a delta between
+        the old and the new.
+
+        Returns:
+            (prev_group, delta_ids), where both may be None.
+        """
+
+        def _get_state_group_delta_txn(txn):
+            prev_group = self._simple_select_one_onecol_txn(
+                txn,
+                table="state_group_edges",
+                keyvalues={"state_group": state_group},
+                retcol="prev_state_group",
+                allow_none=True,
+            )
+
+            if not prev_group:
+                return _GetStateGroupDelta(None, None)
+
+            delta_ids = self._simple_select_list_txn(
+                txn,
+                table="state_groups_state",
+                keyvalues={"state_group": state_group},
+                retcols=("type", "state_key", "event_id"),
+            )
+
+            return _GetStateGroupDelta(
+                prev_group,
+                {(row["type"], row["state_key"]): row["event_id"] for row in delta_ids},
+            )
+
+        return self.runInteraction("get_state_group_delta", _get_state_group_delta_txn)
+
+    @defer.inlineCallbacks
+    def get_state_groups_ids(self, _room_id, event_ids):
+        """Get the event IDs of all the state for the state groups for the given events
+
+        Args:
+            _room_id (str): id of the room for these events
+            event_ids (iterable[str]): ids of the events
+
+        Returns:
+            Deferred[dict[int, dict[tuple[str, str], str]]]:
+                dict of state_group_id -> (dict of (type, state_key) -> event id)
+        """
+        if not event_ids:
+            return {}
+
+        event_to_groups = yield self._get_state_group_for_events(event_ids)
+
+        groups = set(itervalues(event_to_groups))
+        group_to_state = yield self._get_state_for_groups(groups)
+
+        return group_to_state
+
+    @defer.inlineCallbacks
+    def get_state_ids_for_group(self, state_group):
+        """Get the event IDs of all the state in the given state group
+
+        Args:
+            state_group (int)
+
+        Returns:
+            Deferred[dict]: Resolves to a map of (type, state_key) -> event_id
+        """
+        group_to_state = yield self._get_state_for_groups((state_group,))
+
+        return group_to_state[state_group]
+
+    @defer.inlineCallbacks
+    def get_state_groups(self, room_id, event_ids):
+        """ Get the state groups for the given list of event_ids
+
+        Returns:
+            Deferred[dict[int, list[EventBase]]]:
+                dict of state_group_id -> list of state events.
+        """
+        if not event_ids:
+            return {}
+
+        group_to_ids = yield self.get_state_groups_ids(room_id, event_ids)
+
+        state_event_map = yield self.get_events(
+            [
+                ev_id
+                for group_ids in itervalues(group_to_ids)
+                for ev_id in itervalues(group_ids)
+            ],
+            get_prev_content=False,
+        )
+
+        return {
+            group: [
+                state_event_map[v]
+                for v in itervalues(event_id_map)
+                if v in state_event_map
+            ]
+            for group, event_id_map in iteritems(group_to_ids)
+        }
+
+    @defer.inlineCallbacks
+    def _get_state_groups_from_groups(self, groups, state_filter):
+        """Returns the state groups for a given set of groups, filtering on
+        types of state events.
+
+        Args:
+            groups(list[int]): list of state group IDs to query
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+        Returns:
+            Deferred[dict[int, dict[tuple[str, str], str]]]:
+                dict of state_group_id -> (dict of (type, state_key) -> event id)
+        """
+        results = {}
+
+        chunks = [groups[i : i + 100] for i in range(0, len(groups), 100)]
+        for chunk in chunks:
+            res = yield self.runInteraction(
+                "_get_state_groups_from_groups",
+                self._get_state_groups_from_groups_txn,
+                chunk,
+                state_filter,
+            )
+            results.update(res)
+
+        return results
+
+    @defer.inlineCallbacks
+    def get_state_for_events(self, event_ids, state_filter=StateFilter.all()):
+        """Given a list of event_ids and type tuples, return a list of state
+        dicts for each event.
+
+        Args:
+            event_ids (list[string])
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            deferred: A dict of (event_id) -> (type, state_key) -> [state_events]
+        """
+        event_to_groups = yield self._get_state_group_for_events(event_ids)
+
+        groups = set(itervalues(event_to_groups))
+        group_to_state = yield self._get_state_for_groups(groups, state_filter)
+
+        state_event_map = yield self.get_events(
+            [ev_id for sd in itervalues(group_to_state) for ev_id in itervalues(sd)],
+            get_prev_content=False,
+        )
+
+        event_to_state = {
+            event_id: {
+                k: state_event_map[v]
+                for k, v in iteritems(group_to_state[group])
+                if v in state_event_map
+            }
+            for event_id, group in iteritems(event_to_groups)
+        }
+
+        return {event: event_to_state[event] for event in event_ids}
+
+    @defer.inlineCallbacks
+    def get_state_ids_for_events(self, event_ids, state_filter=StateFilter.all()):
+        """
+        Get the state dicts corresponding to a list of events, containing the event_ids
+        of the state events (as opposed to the events themselves)
+
+        Args:
+            event_ids(list(str)): events whose state should be returned
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            A deferred dict from event_id -> (type, state_key) -> event_id
+        """
+        event_to_groups = yield self._get_state_group_for_events(event_ids)
+
+        groups = set(itervalues(event_to_groups))
+        group_to_state = yield self._get_state_for_groups(groups, state_filter)
+
+        event_to_state = {
+            event_id: group_to_state[group]
+            for event_id, group in iteritems(event_to_groups)
+        }
+
+        return {event: event_to_state[event] for event in event_ids}
+
+    @defer.inlineCallbacks
+    def get_state_for_event(self, event_id, state_filter=StateFilter.all()):
+        """
+        Get the state dict corresponding to a particular event
+
+        Args:
+            event_id(str): event whose state should be returned
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            A deferred dict from (type, state_key) -> state_event
+        """
+        state_map = yield self.get_state_for_events([event_id], state_filter)
+        return state_map[event_id]
+
+    @defer.inlineCallbacks
+    def get_state_ids_for_event(self, event_id, state_filter=StateFilter.all()):
+        """
+        Get the state dict corresponding to a particular event
+
+        Args:
+            event_id(str): event whose state should be returned
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            A deferred dict from (type, state_key) -> state_event
+        """
+        state_map = yield self.get_state_ids_for_events([event_id], state_filter)
+        return state_map[event_id]
+
+    @cached(max_entries=50000)
+    def _get_state_group_for_event(self, event_id):
+        return self._simple_select_one_onecol(
+            table="event_to_state_groups",
+            keyvalues={"event_id": event_id},
+            retcol="state_group",
+            allow_none=True,
+            desc="_get_state_group_for_event",
+        )
+
+    @cachedList(
+        cached_method_name="_get_state_group_for_event",
+        list_name="event_ids",
+        num_args=1,
+        inlineCallbacks=True,
+    )
+    def _get_state_group_for_events(self, event_ids):
+        """Returns mapping event_id -> state_group
+        """
+        rows = yield self._simple_select_many_batch(
+            table="event_to_state_groups",
+            column="event_id",
+            iterable=event_ids,
+            keyvalues={},
+            retcols=("event_id", "state_group"),
+            desc="_get_state_group_for_events",
+        )
+
+        return {row["event_id"]: row["state_group"] for row in rows}
+
+    def _get_state_for_group_using_cache(self, cache, group, state_filter):
+        """Checks if group is in cache. See `_get_state_for_groups`
+
+        Args:
+            cache(DictionaryCache): the state group cache to use
+            group(int): The state group to lookup
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns 2-tuple (`state_dict`, `got_all`).
+        `got_all` is a bool indicating if we successfully retrieved all
+        requests state from the cache, if False we need to query the DB for the
+        missing state.
+        """
+        is_all, known_absent, state_dict_ids = cache.get(group)
+
+        if is_all or state_filter.is_full():
+            # Either we have everything or want everything, either way
+            # `is_all` tells us whether we've gotten everything.
+            return state_filter.filter_state(state_dict_ids), is_all
+
+        # tracks whether any of our requested types are missing from the cache
+        missing_types = False
+
+        if state_filter.has_wildcards():
+            # We don't know if we fetched all the state keys for the types in
+            # the filter that are wildcards, so we have to assume that we may
+            # have missed some.
+            missing_types = True
+        else:
+            # There aren't any wild cards, so `concrete_types()` returns the
+            # complete list of event types we're wanting.
+            for key in state_filter.concrete_types():
+                if key not in state_dict_ids and key not in known_absent:
+                    missing_types = True
+                    break
+
+        return state_filter.filter_state(state_dict_ids), not missing_types
+
+    @defer.inlineCallbacks
+    def _get_state_for_groups(self, groups, state_filter=StateFilter.all()):
+        """Gets the state at each of a list of state groups, optionally
+        filtering by type/state_key
+
+        Args:
+            groups (iterable[int]): list of state groups for which we want
+                to get the state.
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+        Returns:
+            Deferred[dict[int, dict[tuple[str, str], str]]]:
+                dict of state_group_id -> (dict of (type, state_key) -> event id)
+        """
+
+        member_filter, non_member_filter = state_filter.get_member_split()
+
+        # Now we look them up in the member and non-member caches
+        non_member_state, incomplete_groups_nm, = (
+            yield self._get_state_for_groups_using_cache(
+                groups, self._state_group_cache, state_filter=non_member_filter
+            )
+        )
+
+        member_state, incomplete_groups_m, = (
+            yield self._get_state_for_groups_using_cache(
+                groups, self._state_group_members_cache, state_filter=member_filter
+            )
+        )
+
+        state = dict(non_member_state)
+        for group in groups:
+            state[group].update(member_state[group])
+
+        # Now fetch any missing groups from the database
+
+        incomplete_groups = incomplete_groups_m | incomplete_groups_nm
+
+        if not incomplete_groups:
+            return state
+
+        cache_sequence_nm = self._state_group_cache.sequence
+        cache_sequence_m = self._state_group_members_cache.sequence
+
+        # Help the cache hit ratio by expanding the filter a bit
+        db_state_filter = state_filter.return_expanded()
+
+        group_to_state_dict = yield self._get_state_groups_from_groups(
+            list(incomplete_groups), state_filter=db_state_filter
+        )
+
+        # Now lets update the caches
+        self._insert_into_cache(
+            group_to_state_dict,
+            db_state_filter,
+            cache_seq_num_members=cache_sequence_m,
+            cache_seq_num_non_members=cache_sequence_nm,
+        )
+
+        # And finally update the result dict, by filtering out any extra
+        # stuff we pulled out of the database.
+        for group, group_state_dict in iteritems(group_to_state_dict):
+            # We just replace any existing entries, as we will have loaded
+            # everything we need from the database anyway.
+            state[group] = state_filter.filter_state(group_state_dict)
+
+        return state
+
+    def _get_state_for_groups_using_cache(self, groups, cache, state_filter):
+        """Gets the state at each of a list of state groups, optionally
+        filtering by type/state_key, querying from a specific cache.
+
+        Args:
+            groups (iterable[int]): list of state groups for which we want
+                to get the state.
+            cache (DictionaryCache): the cache of group ids to state dicts which
+                we will pass through - either the normal state cache or the specific
+                members state cache.
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            tuple[dict[int, dict[tuple[str, str], str]], set[int]]: Tuple of
+            dict of state_group_id -> (dict of (type, state_key) -> event id)
+            of entries in the cache, and the state group ids either missing
+            from the cache or incomplete.
+        """
+        results = {}
+        incomplete_groups = set()
+        for group in set(groups):
+            state_dict_ids, got_all = self._get_state_for_group_using_cache(
+                cache, group, state_filter
+            )
+            results[group] = state_dict_ids
+
+            if not got_all:
+                incomplete_groups.add(group)
+
+        return results, incomplete_groups
+
+    def _insert_into_cache(
+        self,
+        group_to_state_dict,
+        state_filter,
+        cache_seq_num_members,
+        cache_seq_num_non_members,
+    ):
+        """Inserts results from querying the database into the relevant cache.
+
+        Args:
+            group_to_state_dict (dict): The new entries pulled from database.
+                Map from state group to state dict
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+            cache_seq_num_members (int): Sequence number of member cache since
+                last lookup in cache
+            cache_seq_num_non_members (int): Sequence number of member cache since
+                last lookup in cache
+        """
+
+        # We need to work out which types we've fetched from the DB for the
+        # member vs non-member caches. This should be as accurate as possible,
+        # but can be an underestimate (e.g. when we have wild cards)
+
+        member_filter, non_member_filter = state_filter.get_member_split()
+        if member_filter.is_full():
+            # We fetched all member events
+            member_types = None
+        else:
+            # `concrete_types()` will only return a subset when there are wild
+            # cards in the filter, but that's fine.
+            member_types = member_filter.concrete_types()
+
+        if non_member_filter.is_full():
+            # We fetched all non member events
+            non_member_types = None
+        else:
+            non_member_types = non_member_filter.concrete_types()
+
+        for group, group_state_dict in iteritems(group_to_state_dict):
+            state_dict_members = {}
+            state_dict_non_members = {}
+
+            for k, v in iteritems(group_state_dict):
+                if k[0] == EventTypes.Member:
+                    state_dict_members[k] = v
+                else:
+                    state_dict_non_members[k] = v
+
+            self._state_group_members_cache.update(
+                cache_seq_num_members,
+                key=group,
+                value=state_dict_members,
+                fetched_keys=member_types,
+            )
+
+            self._state_group_cache.update(
+                cache_seq_num_non_members,
+                key=group,
+                value=state_dict_non_members,
+                fetched_keys=non_member_types,
+            )
+
+    def store_state_group(
+        self, event_id, room_id, prev_group, delta_ids, current_state_ids
+    ):
+        """Store a new set of state, returning a newly assigned state group.
+
+        Args:
+            event_id (str): The event ID for which the state was calculated
+            room_id (str)
+            prev_group (int|None): A previous state group for the room, optional.
+            delta_ids (dict|None): The delta between state at `prev_group` and
+                `current_state_ids`, if `prev_group` was given. Same format as
+                `current_state_ids`.
+            current_state_ids (dict): The state to store. Map of (type, state_key)
+                to event_id.
+
+        Returns:
+            Deferred[int]: The state group ID
+        """
+
+        def _store_state_group_txn(txn):
+            if current_state_ids is None:
+                # AFAIK, this can never happen
+                raise Exception("current_state_ids cannot be None")
+
+            state_group = self.database_engine.get_next_state_group_id(txn)
+
+            self._simple_insert_txn(
+                txn,
+                table="state_groups",
+                values={"id": state_group, "room_id": room_id, "event_id": event_id},
+            )
+
+            # We persist as a delta if we can, while also ensuring the chain
+            # of deltas isn't tooo long, as otherwise read performance degrades.
+            if prev_group:
+                is_in_db = self._simple_select_one_onecol_txn(
+                    txn,
+                    table="state_groups",
+                    keyvalues={"id": prev_group},
+                    retcol="id",
+                    allow_none=True,
+                )
+                if not is_in_db:
+                    raise Exception(
+                        "Trying to persist state with unpersisted prev_group: %r"
+                        % (prev_group,)
+                    )
+
+                potential_hops = self._count_state_group_hops_txn(txn, prev_group)
+            if prev_group and potential_hops < MAX_STATE_DELTA_HOPS:
+                self._simple_insert_txn(
+                    txn,
+                    table="state_group_edges",
+                    values={"state_group": state_group, "prev_state_group": prev_group},
+                )
+
+                self._simple_insert_many_txn(
+                    txn,
+                    table="state_groups_state",
+                    values=[
+                        {
+                            "state_group": state_group,
+                            "room_id": room_id,
+                            "type": key[0],
+                            "state_key": key[1],
+                            "event_id": state_id,
+                        }
+                        for key, state_id in iteritems(delta_ids)
+                    ],
+                )
+            else:
+                self._simple_insert_many_txn(
+                    txn,
+                    table="state_groups_state",
+                    values=[
+                        {
+                            "state_group": state_group,
+                            "room_id": room_id,
+                            "type": key[0],
+                            "state_key": key[1],
+                            "event_id": state_id,
+                        }
+                        for key, state_id in iteritems(current_state_ids)
+                    ],
+                )
+
+            # Prefill the state group caches with this group.
+            # It's fine to use the sequence like this as the state group map
+            # is immutable. (If the map wasn't immutable then this prefill could
+            # race with another update)
+
+            current_member_state_ids = {
+                s: ev
+                for (s, ev) in iteritems(current_state_ids)
+                if s[0] == EventTypes.Member
+            }
+            txn.call_after(
+                self._state_group_members_cache.update,
+                self._state_group_members_cache.sequence,
+                key=state_group,
+                value=dict(current_member_state_ids),
+            )
+
+            current_non_member_state_ids = {
+                s: ev
+                for (s, ev) in iteritems(current_state_ids)
+                if s[0] != EventTypes.Member
+            }
+            txn.call_after(
+                self._state_group_cache.update,
+                self._state_group_cache.sequence,
+                key=state_group,
+                value=dict(current_non_member_state_ids),
+            )
+
+            return state_group
+
+        return self.runInteraction("store_state_group", _store_state_group_txn)
+
+
+class StateBackgroundUpdateStore(
+    StateGroupBackgroundUpdateStore, BackgroundUpdateStore
+):
+
+    STATE_GROUP_DEDUPLICATION_UPDATE_NAME = "state_group_state_deduplication"
+    STATE_GROUP_INDEX_UPDATE_NAME = "state_group_state_type_index"
+    CURRENT_STATE_INDEX_UPDATE_NAME = "current_state_members_idx"
+    EVENT_STATE_GROUP_INDEX_UPDATE_NAME = "event_to_state_groups_sg_index"
+
+    def __init__(self, db_conn, hs):
+        super(StateBackgroundUpdateStore, self).__init__(db_conn, hs)
+        self.register_background_update_handler(
+            self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME,
+            self._background_deduplicate_state,
+        )
+        self.register_background_update_handler(
+            self.STATE_GROUP_INDEX_UPDATE_NAME, self._background_index_state
+        )
+        self.register_background_index_update(
+            self.CURRENT_STATE_INDEX_UPDATE_NAME,
+            index_name="current_state_events_member_index",
+            table="current_state_events",
+            columns=["state_key"],
+            where_clause="type='m.room.member'",
+        )
+        self.register_background_index_update(
+            self.EVENT_STATE_GROUP_INDEX_UPDATE_NAME,
+            index_name="event_to_state_groups_sg_index",
+            table="event_to_state_groups",
+            columns=["state_group"],
+        )
+
+    @defer.inlineCallbacks
+    def _background_deduplicate_state(self, progress, batch_size):
+        """This background update will slowly deduplicate state by reencoding
+        them as deltas.
+        """
+        last_state_group = progress.get("last_state_group", 0)
+        rows_inserted = progress.get("rows_inserted", 0)
+        max_group = progress.get("max_group", None)
+
+        BATCH_SIZE_SCALE_FACTOR = 100
+
+        batch_size = max(1, int(batch_size / BATCH_SIZE_SCALE_FACTOR))
+
+        if max_group is None:
+            rows = yield self._execute(
+                "_background_deduplicate_state",
+                None,
+                "SELECT coalesce(max(id), 0) FROM state_groups",
+            )
+            max_group = rows[0][0]
+
+        def reindex_txn(txn):
+            new_last_state_group = last_state_group
+            for count in range(batch_size):
+                txn.execute(
+                    "SELECT id, room_id FROM state_groups"
+                    " WHERE ? < id AND id <= ?"
+                    " ORDER BY id ASC"
+                    " LIMIT 1",
+                    (new_last_state_group, max_group),
+                )
+                row = txn.fetchone()
+                if row:
+                    state_group, room_id = row
+
+                if not row or not state_group:
+                    return True, count
+
+                txn.execute(
+                    "SELECT state_group FROM state_group_edges"
+                    " WHERE state_group = ?",
+                    (state_group,),
+                )
+
+                # If we reach a point where we've already started inserting
+                # edges we should stop.
+                if txn.fetchall():
+                    return True, count
+
+                txn.execute(
+                    "SELECT coalesce(max(id), 0) FROM state_groups"
+                    " WHERE id < ? AND room_id = ?",
+                    (state_group, room_id),
+                )
+                prev_group, = txn.fetchone()
+                new_last_state_group = state_group
+
+                if prev_group:
+                    potential_hops = self._count_state_group_hops_txn(txn, prev_group)
+                    if potential_hops >= MAX_STATE_DELTA_HOPS:
+                        # We want to ensure chains are at most this long,#
+                        # otherwise read performance degrades.
+                        continue
+
+                    prev_state = self._get_state_groups_from_groups_txn(
+                        txn, [prev_group]
+                    )
+                    prev_state = prev_state[prev_group]
+
+                    curr_state = self._get_state_groups_from_groups_txn(
+                        txn, [state_group]
+                    )
+                    curr_state = curr_state[state_group]
+
+                    if not set(prev_state.keys()) - set(curr_state.keys()):
+                        # We can only do a delta if the current has a strict super set
+                        # of keys
+
+                        delta_state = {
+                            key: value
+                            for key, value in iteritems(curr_state)
+                            if prev_state.get(key, None) != value
+                        }
+
+                        self._simple_delete_txn(
+                            txn,
+                            table="state_group_edges",
+                            keyvalues={"state_group": state_group},
+                        )
+
+                        self._simple_insert_txn(
+                            txn,
+                            table="state_group_edges",
+                            values={
+                                "state_group": state_group,
+                                "prev_state_group": prev_group,
+                            },
+                        )
+
+                        self._simple_delete_txn(
+                            txn,
+                            table="state_groups_state",
+                            keyvalues={"state_group": state_group},
+                        )
+
+                        self._simple_insert_many_txn(
+                            txn,
+                            table="state_groups_state",
+                            values=[
+                                {
+                                    "state_group": state_group,
+                                    "room_id": room_id,
+                                    "type": key[0],
+                                    "state_key": key[1],
+                                    "event_id": state_id,
+                                }
+                                for key, state_id in iteritems(delta_state)
+                            ],
+                        )
+
+            progress = {
+                "last_state_group": state_group,
+                "rows_inserted": rows_inserted + batch_size,
+                "max_group": max_group,
+            }
+
+            self._background_update_progress_txn(
+                txn, self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME, progress
+            )
+
+            return False, batch_size
+
+        finished, result = yield self.runInteraction(
+            self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME, reindex_txn
+        )
+
+        if finished:
+            yield self._end_background_update(
+                self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME
+            )
+
+        return result * BATCH_SIZE_SCALE_FACTOR
+
+    @defer.inlineCallbacks
+    def _background_index_state(self, progress, batch_size):
+        def reindex_txn(conn):
+            conn.rollback()
+            if isinstance(self.database_engine, PostgresEngine):
+                # postgres insists on autocommit for the index
+                conn.set_session(autocommit=True)
+                try:
+                    txn = conn.cursor()
+                    txn.execute(
+                        "CREATE INDEX CONCURRENTLY state_groups_state_type_idx"
+                        " ON state_groups_state(state_group, type, state_key)"
+                    )
+                    txn.execute("DROP INDEX IF EXISTS state_groups_state_id")
+                finally:
+                    conn.set_session(autocommit=False)
+            else:
+                txn = conn.cursor()
+                txn.execute(
+                    "CREATE INDEX state_groups_state_type_idx"
+                    " ON state_groups_state(state_group, type, state_key)"
+                )
+                txn.execute("DROP INDEX IF EXISTS state_groups_state_id")
+
+        yield self.runWithConnection(reindex_txn)
+
+        yield self._end_background_update(self.STATE_GROUP_INDEX_UPDATE_NAME)
+
+        return 1
+
+
+class StateStore(StateGroupWorkerStore, StateBackgroundUpdateStore):
+    """ Keeps track of the state at a given event.
+
+    This is done by the concept of `state groups`. Every event is a assigned
+    a state group (identified by an arbitrary string), which references a
+    collection of state events. The current state of an event is then the
+    collection of state events referenced by the event's state group.
+
+    Hence, every change in the current state causes a new state group to be
+    generated. However, if no change happens (e.g., if we get a message event
+    with only one parent it inherits the state group from its parent.)
+
+    There are three tables:
+      * `state_groups`: Stores group name, first event with in the group and
+        room id.
+      * `event_to_state_groups`: Maps events to state groups.
+      * `state_groups_state`: Maps state group to state events.
+    """
+
+    def __init__(self, db_conn, hs):
+        super(StateStore, self).__init__(db_conn, hs)
+
+    def _store_event_state_mappings_txn(self, txn, events_and_contexts):
+        state_groups = {}
+        for event, context in events_and_contexts:
+            if event.internal_metadata.is_outlier():
+                continue
+
+            # if the event was rejected, just give it the same state as its
+            # predecessor.
+            if context.rejected:
+                state_groups[event.event_id] = context.prev_group
+                continue
+
+            state_groups[event.event_id] = context.state_group
+
+        self._simple_insert_many_txn(
+            txn,
+            table="event_to_state_groups",
+            values=[
+                {"state_group": state_group_id, "event_id": event_id}
+                for event_id, state_group_id in iteritems(state_groups)
+            ],
+        )
+
+        for event_id, state_group_id in iteritems(state_groups):
+            txn.call_after(
+                self._get_state_group_for_event.prefill, (event_id,), state_group_id
+            )
diff --git a/synapse/storage/state_deltas.py b/synapse/storage/data_stores/main/state_deltas.py
index 28f33ec18f..28f33ec18f 100644
--- a/synapse/storage/state_deltas.py
+++ b/synapse/storage/data_stores/main/state_deltas.py
diff --git a/synapse/storage/stats.py b/synapse/storage/data_stores/main/stats.py
index 7c224cd3d9..5ab639b2ad 100644
--- a/synapse/storage/stats.py
+++ b/synapse/storage/data_stores/main/stats.py
@@ -21,8 +21,8 @@ from twisted.internet import defer
 from twisted.internet.defer import DeferredLock
 
 from synapse.api.constants import EventTypes, Membership
-from synapse.storage import PostgresEngine
-from synapse.storage.state_deltas import StateDeltasStore
+from synapse.storage.data_stores.main.state_deltas import StateDeltasStore
+from synapse.storage.engines import PostgresEngine
 from synapse.util.caches.descriptors import cached
 
 logger = logging.getLogger(__name__)
diff --git a/synapse/storage/stream.py b/synapse/storage/data_stores/main/stream.py
index 490454f19a..263999dfca 100644
--- a/synapse/storage/stream.py
+++ b/synapse/storage/data_stores/main/stream.py
@@ -43,8 +43,8 @@ from twisted.internet import defer
 
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.storage._base import SQLBaseStore
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
 from synapse.storage.engines import PostgresEngine
-from synapse.storage.events_worker import EventsWorkerStore
 from synapse.types import RoomStreamToken
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
diff --git a/synapse/storage/tags.py b/synapse/storage/data_stores/main/tags.py
index 20dd6bd53d..10d1887f75 100644
--- a/synapse/storage/tags.py
+++ b/synapse/storage/data_stores/main/tags.py
@@ -22,7 +22,7 @@ from canonicaljson import json
 
 from twisted.internet import defer
 
-from synapse.storage.account_data import AccountDataWorkerStore
+from synapse.storage.data_stores.main.account_data import AccountDataWorkerStore
 from synapse.util.caches.descriptors import cached
 
 logger = logging.getLogger(__name__)
diff --git a/synapse/storage/transactions.py b/synapse/storage/data_stores/main/transactions.py
index 289c117396..01b1be5e14 100644
--- a/synapse/storage/transactions.py
+++ b/synapse/storage/data_stores/main/transactions.py
@@ -23,10 +23,9 @@ from canonicaljson import encode_canonical_json
 from twisted.internet import defer
 
 from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.storage._base import SQLBaseStore, db_to_json
 from synapse.util.caches.expiringcache import ExpiringCache
 
-from ._base import SQLBaseStore, db_to_json
-
 # py2 sqlite has buffer hardcoded as only binary type, so we must use it,
 # despite being deprecated and removed in favor of memoryview
 if six.PY2:
diff --git a/synapse/storage/user_directory.py b/synapse/storage/data_stores/main/user_directory.py
index 1b1e4751b9..652abe0e6a 100644
--- a/synapse/storage/user_directory.py
+++ b/synapse/storage/data_stores/main/user_directory.py
@@ -20,9 +20,9 @@ from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, JoinRules
 from synapse.storage.background_updates import BackgroundUpdateStore
+from synapse.storage.data_stores.main.state import StateFilter
+from synapse.storage.data_stores.main.state_deltas import StateDeltasStore
 from synapse.storage.engines import PostgresEngine, Sqlite3Engine
-from synapse.storage.state import StateFilter
-from synapse.storage.state_deltas import StateDeltasStore
 from synapse.types import get_domain_from_id, get_localpart_from_id
 from synapse.util.caches.descriptors import cached
 
diff --git a/synapse/storage/user_erasure_store.py b/synapse/storage/data_stores/main/user_erasure_store.py
index aa4f0da5f0..aa4f0da5f0 100644
--- a/synapse/storage/user_erasure_store.py
+++ b/synapse/storage/data_stores/main/user_erasure_store.py
diff --git a/synapse/storage/keys.py b/synapse/storage/keys.py
index e72f89e446..4769b21529 100644
--- a/synapse/storage/keys.py
+++ b/synapse/storage/keys.py
@@ -14,208 +14,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import itertools
 import logging
 
-import six
-
 import attr
-from signedjson.key import decode_verify_key_bytes
-
-from synapse.util import batch_iter
-from synapse.util.caches.descriptors import cached, cachedList
-
-from ._base import SQLBaseStore
 
 logger = logging.getLogger(__name__)
 
-# py2 sqlite has buffer hardcoded as only binary type, so we must use it,
-# despite being deprecated and removed in favor of memoryview
-if six.PY2:
-    db_binary_type = six.moves.builtins.buffer
-else:
-    db_binary_type = memoryview
-
 
 @attr.s(slots=True, frozen=True)
 class FetchKeyResult(object):
     verify_key = attr.ib()  # VerifyKey: the key itself
     valid_until_ts = attr.ib()  # int: how long we can use this key for
-
-
-class KeyStore(SQLBaseStore):
-    """Persistence for signature verification keys
-    """
-
-    @cached()
-    def _get_server_verify_key(self, server_name_and_key_id):
-        raise NotImplementedError()
-
-    @cachedList(
-        cached_method_name="_get_server_verify_key", list_name="server_name_and_key_ids"
-    )
-    def get_server_verify_keys(self, server_name_and_key_ids):
-        """
-        Args:
-            server_name_and_key_ids (iterable[Tuple[str, str]]):
-                iterable of (server_name, key-id) tuples to fetch keys for
-
-        Returns:
-            Deferred: resolves to dict[Tuple[str, str], FetchKeyResult|None]:
-                map from (server_name, key_id) -> FetchKeyResult, or None if the key is
-                unknown
-        """
-        keys = {}
-
-        def _get_keys(txn, batch):
-            """Processes a batch of keys to fetch, and adds the result to `keys`."""
-
-            # batch_iter always returns tuples so it's safe to do len(batch)
-            sql = (
-                "SELECT server_name, key_id, verify_key, ts_valid_until_ms "
-                "FROM server_signature_keys WHERE 1=0"
-            ) + " OR (server_name=? AND key_id=?)" * len(batch)
-
-            txn.execute(sql, tuple(itertools.chain.from_iterable(batch)))
-
-            for row in txn:
-                server_name, key_id, key_bytes, ts_valid_until_ms = row
-
-                if ts_valid_until_ms is None:
-                    # Old keys may be stored with a ts_valid_until_ms of null,
-                    # in which case we treat this as if it was set to `0`, i.e.
-                    # it won't match key requests that define a minimum
-                    # `ts_valid_until_ms`.
-                    ts_valid_until_ms = 0
-
-                res = FetchKeyResult(
-                    verify_key=decode_verify_key_bytes(key_id, bytes(key_bytes)),
-                    valid_until_ts=ts_valid_until_ms,
-                )
-                keys[(server_name, key_id)] = res
-
-        def _txn(txn):
-            for batch in batch_iter(server_name_and_key_ids, 50):
-                _get_keys(txn, batch)
-            return keys
-
-        return self.runInteraction("get_server_verify_keys", _txn)
-
-    def store_server_verify_keys(self, from_server, ts_added_ms, verify_keys):
-        """Stores NACL verification keys for remote servers.
-        Args:
-            from_server (str): Where the verification keys were looked up
-            ts_added_ms (int): The time to record that the key was added
-            verify_keys (iterable[tuple[str, str, FetchKeyResult]]):
-                keys to be stored. Each entry is a triplet of
-                (server_name, key_id, key).
-        """
-        key_values = []
-        value_values = []
-        invalidations = []
-        for server_name, key_id, fetch_result in verify_keys:
-            key_values.append((server_name, key_id))
-            value_values.append(
-                (
-                    from_server,
-                    ts_added_ms,
-                    fetch_result.valid_until_ts,
-                    db_binary_type(fetch_result.verify_key.encode()),
-                )
-            )
-            # invalidate takes a tuple corresponding to the params of
-            # _get_server_verify_key. _get_server_verify_key only takes one
-            # param, which is itself the 2-tuple (server_name, key_id).
-            invalidations.append((server_name, key_id))
-
-        def _invalidate(res):
-            f = self._get_server_verify_key.invalidate
-            for i in invalidations:
-                f((i,))
-            return res
-
-        return self.runInteraction(
-            "store_server_verify_keys",
-            self._simple_upsert_many_txn,
-            table="server_signature_keys",
-            key_names=("server_name", "key_id"),
-            key_values=key_values,
-            value_names=(
-                "from_server",
-                "ts_added_ms",
-                "ts_valid_until_ms",
-                "verify_key",
-            ),
-            value_values=value_values,
-        ).addCallback(_invalidate)
-
-    def store_server_keys_json(
-        self, server_name, key_id, from_server, ts_now_ms, ts_expires_ms, key_json_bytes
-    ):
-        """Stores the JSON bytes for a set of keys from a server
-        The JSON should be signed by the originating server, the intermediate
-        server, and by this server. Updates the value for the
-        (server_name, key_id, from_server) triplet if one already existed.
-        Args:
-            server_name (str): The name of the server.
-            key_id (str): The identifer of the key this JSON is for.
-            from_server (str): The server this JSON was fetched from.
-            ts_now_ms (int): The time now in milliseconds.
-            ts_valid_until_ms (int): The time when this json stops being valid.
-            key_json (bytes): The encoded JSON.
-        """
-        return self._simple_upsert(
-            table="server_keys_json",
-            keyvalues={
-                "server_name": server_name,
-                "key_id": key_id,
-                "from_server": from_server,
-            },
-            values={
-                "server_name": server_name,
-                "key_id": key_id,
-                "from_server": from_server,
-                "ts_added_ms": ts_now_ms,
-                "ts_valid_until_ms": ts_expires_ms,
-                "key_json": db_binary_type(key_json_bytes),
-            },
-            desc="store_server_keys_json",
-        )
-
-    def get_server_keys_json(self, server_keys):
-        """Retrive the key json for a list of server_keys and key ids.
-        If no keys are found for a given server, key_id and source then
-        that server, key_id, and source triplet entry will be an empty list.
-        The JSON is returned as a byte array so that it can be efficiently
-        used in an HTTP response.
-        Args:
-            server_keys (list): List of (server_name, key_id, source) triplets.
-        Returns:
-            Deferred[dict[Tuple[str, str, str|None], list[dict]]]:
-                Dict mapping (server_name, key_id, source) triplets to lists of dicts
-        """
-
-        def _get_server_keys_json_txn(txn):
-            results = {}
-            for server_name, key_id, from_server in server_keys:
-                keyvalues = {"server_name": server_name}
-                if key_id is not None:
-                    keyvalues["key_id"] = key_id
-                if from_server is not None:
-                    keyvalues["from_server"] = from_server
-                rows = self._simple_select_list_txn(
-                    txn,
-                    "server_keys_json",
-                    keyvalues=keyvalues,
-                    retcols=(
-                        "key_id",
-                        "from_server",
-                        "ts_added_ms",
-                        "ts_valid_until_ms",
-                        "key_json",
-                    ),
-                )
-                results[(server_name, key_id, from_server)] = rows
-            return results
-
-        return self.runInteraction("get_server_keys_json", _get_server_keys_json_txn)
diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py
index e96eed8a6d..2e7753820e 100644
--- a/synapse/storage/prepare_database.py
+++ b/synapse/storage/prepare_database.py
@@ -14,12 +14,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import fnmatch
 import imp
 import logging
 import os
 import re
 
+import attr
+
 from synapse.storage.engines.postgres import PostgresEngine
 
 logger = logging.getLogger(__name__)
@@ -54,6 +55,10 @@ def prepare_database(db_conn, database_engine, config):
             application config, or None if we are connecting to an existing
             database which we expect to be configured already
     """
+
+    # For now we only have the one datastore.
+    data_stores = ["main"]
+
     try:
         cur = db_conn.cursor()
         version_info = _get_or_create_schema_state(cur, database_engine)
@@ -68,10 +73,16 @@ def prepare_database(db_conn, database_engine, config):
                     raise UpgradeDatabaseException("Database needs to be upgraded")
             else:
                 _upgrade_existing_database(
-                    cur, user_version, delta_files, upgraded, database_engine, config
+                    cur,
+                    user_version,
+                    delta_files,
+                    upgraded,
+                    database_engine,
+                    config,
+                    data_stores=data_stores,
                 )
         else:
-            _setup_new_database(cur, database_engine)
+            _setup_new_database(cur, database_engine, data_stores=data_stores)
 
         # check if any of our configured dynamic modules want a database
         if config is not None:
@@ -84,9 +95,10 @@ def prepare_database(db_conn, database_engine, config):
         raise
 
 
-def _setup_new_database(cur, database_engine):
+def _setup_new_database(cur, database_engine, data_stores):
     """Sets up the database by finding a base set of "full schemas" and then
-    applying any necessary deltas.
+    applying any necessary deltas, including schemas from the given data
+    stores.
 
     The "full_schemas" directory has subdirectories named after versions. This
     function searches for the highest version less than or equal to
@@ -111,52 +123,78 @@ def _setup_new_database(cur, database_engine):
 
     In the example foo.sql and bar.sql would be run, and then any delta files
     for versions strictly greater than 11.
+
+    Note: we apply the full schemas and deltas from the top level `schema/`
+    folder as well those in the data stores specified.
+
+    Args:
+        cur (Cursor): a database cursor
+        database_engine (DatabaseEngine)
+        data_stores (list[str]): The names of the data stores to instantiate
+            on the given database.
     """
     current_dir = os.path.join(dir_path, "schema", "full_schemas")
     directory_entries = os.listdir(current_dir)
 
-    valid_dirs = []
-    pattern = re.compile(r"^\d+(\.sql)?$")
-
-    if isinstance(database_engine, PostgresEngine):
-        specific = "postgres"
-    else:
-        specific = "sqlite"
-
-    specific_pattern = re.compile(r"^\d+(\.sql." + specific + r")?$")
+    # First we find the highest full schema version we have
+    valid_versions = []
 
     for filename in directory_entries:
-        match = pattern.match(filename) or specific_pattern.match(filename)
-        abs_path = os.path.join(current_dir, filename)
-        if match and os.path.isdir(abs_path):
-            ver = int(match.group(0))
-            if ver <= SCHEMA_VERSION:
-                valid_dirs.append((ver, abs_path))
-        else:
-            logger.debug("Ignoring entry '%s' in 'full_schemas'", filename)
+        try:
+            ver = int(filename)
+        except ValueError:
+            continue
+
+        if ver <= SCHEMA_VERSION:
+            valid_versions.append(ver)
 
-    if not valid_dirs:
+    if not valid_versions:
         raise PrepareDatabaseException(
             "Could not find a suitable base set of full schemas"
         )
 
-    max_current_ver, sql_dir = max(valid_dirs, key=lambda x: x[0])
+    max_current_ver = max(valid_versions)
 
     logger.debug("Initialising schema v%d", max_current_ver)
 
-    directory_entries = os.listdir(sql_dir)
+    # Now lets find all the full schema files, both in the global schema and
+    # in data store schemas.
+    directories = [os.path.join(current_dir, str(max_current_ver))]
+    directories.extend(
+        os.path.join(
+            dir_path,
+            "data_stores",
+            data_store,
+            "schema",
+            "full_schemas",
+            str(max_current_ver),
+        )
+        for data_store in data_stores
+    )
+
+    directory_entries = []
+    for directory in directories:
+        directory_entries.extend(
+            _DirectoryListing(file_name, os.path.join(directory, file_name))
+            for file_name in os.listdir(directory)
+        )
+
+    if isinstance(database_engine, PostgresEngine):
+        specific = "postgres"
+    else:
+        specific = "sqlite"
 
-    for filename in sorted(
-        fnmatch.filter(directory_entries, "*.sql")
-        + fnmatch.filter(directory_entries, "*.sql." + specific)
-    ):
-        sql_loc = os.path.join(sql_dir, filename)
-        logger.debug("Applying schema %s", sql_loc)
-        executescript(cur, sql_loc)
+    directory_entries.sort()
+    for entry in directory_entries:
+        if entry.file_name.endswith(".sql") or entry.file_name.endswith(
+            ".sql." + specific
+        ):
+            logger.debug("Applying schema %s", entry.absolute_path)
+            executescript(cur, entry.absolute_path)
 
     cur.execute(
         database_engine.convert_param_style(
-            "INSERT INTO schema_version (version, upgraded)" " VALUES (?,?)"
+            "INSERT INTO schema_version (version, upgraded) VALUES (?,?)"
         ),
         (max_current_ver, False),
     )
@@ -168,6 +206,7 @@ def _setup_new_database(cur, database_engine):
         upgraded=False,
         database_engine=database_engine,
         config=None,
+        data_stores=data_stores,
         is_empty=True,
     )
 
@@ -179,6 +218,7 @@ def _upgrade_existing_database(
     upgraded,
     database_engine,
     config,
+    data_stores,
     is_empty=False,
 ):
     """Upgrades an existing database.
@@ -215,6 +255,10 @@ def _upgrade_existing_database(
     only if `upgraded` is True. Then `foo.sql` and `bar.py` would be run in
     some arbitrary order.
 
+    Note: we apply the delta files from the specified data stores as well as
+    those in the top-level schema. We apply all delta files across data stores
+    for a version before applying those in the next version.
+
     Args:
         cur (Cursor)
         current_version (int): The current version of the schema.
@@ -224,6 +268,14 @@ def _upgrade_existing_database(
             applied deltas or from full schema file. If `True` the function
             will never apply delta files for the given `current_version`, since
             the current_version wasn't generated by applying those delta files.
+        database_engine (DatabaseEngine)
+        config (synapse.config.homeserver.HomeServerConfig|None):
+            application config, or None if we are connecting to an existing
+            database which we expect to be configured already
+        data_stores (list[str]): The names of the data stores to instantiate
+            on the given database.
+        is_empty (bool): Is this a blank database? I.e. do we need to run the
+            upgrade portions of the delta scripts.
     """
 
     if current_version > SCHEMA_VERSION:
@@ -248,24 +300,49 @@ def _upgrade_existing_database(
     for v in range(start_ver, SCHEMA_VERSION + 1):
         logger.info("Upgrading schema to v%d", v)
 
-        delta_dir = os.path.join(dir_path, "schema", "delta", str(v))
+        # We need to search both the global and per data store schema
+        # directories for schema updates.
 
-        try:
-            directory_entries = os.listdir(delta_dir)
-        except OSError:
-            logger.exception("Could not open delta dir for version %d", v)
-            raise UpgradeDatabaseException(
-                "Could not open delta dir for version %d" % (v,)
+        # First we find the directories to search in
+        delta_dir = os.path.join(dir_path, "schema", "delta", str(v))
+        directories = [delta_dir]
+        for data_store in data_stores:
+            directories.append(
+                os.path.join(
+                    dir_path, "data_stores", data_store, "schema", "delta", str(v)
+                )
             )
 
+        # Now find which directories have anything of interest.
+        directory_entries = []
+        for directory in directories:
+            logger.debug("Looking for schema deltas in %s", directory)
+            try:
+                file_names = os.listdir(directory)
+                directory_entries.extend(
+                    _DirectoryListing(file_name, os.path.join(directory, file_name))
+                    for file_name in file_names
+                )
+            except FileNotFoundError:
+                # Data stores can have empty entries for a given version delta.
+                pass
+            except OSError:
+                raise UpgradeDatabaseException(
+                    "Could not open delta dir for version %d: %s" % (v, directory)
+                )
+
+        # We sort to ensure that we apply the delta files in a consistent
+        # order (to avoid bugs caused by inconsistent directory listing order)
         directory_entries.sort()
-        for file_name in directory_entries:
+        for entry in directory_entries:
+            file_name = entry.file_name
             relative_path = os.path.join(str(v), file_name)
-            logger.debug("Found file: %s", relative_path)
+            absolute_path = entry.absolute_path
+
+            logger.debug("Found file: %s (%s)", relative_path, absolute_path)
             if relative_path in applied_delta_files:
                 continue
 
-            absolute_path = os.path.join(dir_path, "schema", "delta", relative_path)
             root_name, ext = os.path.splitext(file_name)
             if ext == ".py":
                 # This is a python upgrade module. We need to import into some
@@ -448,3 +525,16 @@ def _get_or_create_schema_state(txn, database_engine):
         return current_version, applied_deltas, upgraded
 
     return None
+
+
+@attr.s()
+class _DirectoryListing(object):
+    """Helper class to store schema file name and the
+    absolute path to it.
+
+    These entries get sorted, so for consistency we want to ensure that
+    `file_name` attr is kept first.
+    """
+
+    file_name = attr.ib()
+    absolute_path = attr.ib()
diff --git a/synapse/storage/presence.py b/synapse/storage/presence.py
index 3a641f538b..18a462f0ee 100644
--- a/synapse/storage/presence.py
+++ b/synapse/storage/presence.py
@@ -15,12 +15,7 @@
 
 from collections import namedtuple
 
-from twisted.internet import defer
-
 from synapse.api.constants import PresenceState
-from synapse.storage._base import SQLBaseStore, make_in_list_sql_clause
-from synapse.util import batch_iter
-from synapse.util.caches.descriptors import cached, cachedList
 
 
 class UserPresenceState(
@@ -72,132 +67,3 @@ class UserPresenceState(
             status_msg=None,
             currently_active=False,
         )
-
-
-class PresenceStore(SQLBaseStore):
-    @defer.inlineCallbacks
-    def update_presence(self, presence_states):
-        stream_ordering_manager = self._presence_id_gen.get_next_mult(
-            len(presence_states)
-        )
-
-        with stream_ordering_manager as stream_orderings:
-            yield self.runInteraction(
-                "update_presence",
-                self._update_presence_txn,
-                stream_orderings,
-                presence_states,
-            )
-
-        return stream_orderings[-1], self._presence_id_gen.get_current_token()
-
-    def _update_presence_txn(self, txn, stream_orderings, presence_states):
-        for stream_id, state in zip(stream_orderings, presence_states):
-            txn.call_after(
-                self.presence_stream_cache.entity_has_changed, state.user_id, stream_id
-            )
-            txn.call_after(self._get_presence_for_user.invalidate, (state.user_id,))
-
-        # Actually insert new rows
-        self._simple_insert_many_txn(
-            txn,
-            table="presence_stream",
-            values=[
-                {
-                    "stream_id": stream_id,
-                    "user_id": state.user_id,
-                    "state": state.state,
-                    "last_active_ts": state.last_active_ts,
-                    "last_federation_update_ts": state.last_federation_update_ts,
-                    "last_user_sync_ts": state.last_user_sync_ts,
-                    "status_msg": state.status_msg,
-                    "currently_active": state.currently_active,
-                }
-                for state in presence_states
-            ],
-        )
-
-        # Delete old rows to stop database from getting really big
-        sql = "DELETE FROM presence_stream WHERE stream_id < ? AND "
-
-        for states in batch_iter(presence_states, 50):
-            clause, args = make_in_list_sql_clause(
-                self.database_engine, "user_id", [s.user_id for s in states]
-            )
-            txn.execute(sql + clause, [stream_id] + list(args))
-
-    def get_all_presence_updates(self, last_id, current_id):
-        if last_id == current_id:
-            return defer.succeed([])
-
-        def get_all_presence_updates_txn(txn):
-            sql = (
-                "SELECT stream_id, user_id, state, last_active_ts,"
-                " last_federation_update_ts, last_user_sync_ts, status_msg,"
-                " currently_active"
-                " FROM presence_stream"
-                " WHERE ? < stream_id AND stream_id <= ?"
-            )
-            txn.execute(sql, (last_id, current_id))
-            return txn.fetchall()
-
-        return self.runInteraction(
-            "get_all_presence_updates", get_all_presence_updates_txn
-        )
-
-    @cached()
-    def _get_presence_for_user(self, user_id):
-        raise NotImplementedError()
-
-    @cachedList(
-        cached_method_name="_get_presence_for_user",
-        list_name="user_ids",
-        num_args=1,
-        inlineCallbacks=True,
-    )
-    def get_presence_for_users(self, user_ids):
-        rows = yield self._simple_select_many_batch(
-            table="presence_stream",
-            column="user_id",
-            iterable=user_ids,
-            keyvalues={},
-            retcols=(
-                "user_id",
-                "state",
-                "last_active_ts",
-                "last_federation_update_ts",
-                "last_user_sync_ts",
-                "status_msg",
-                "currently_active",
-            ),
-            desc="get_presence_for_users",
-        )
-
-        for row in rows:
-            row["currently_active"] = bool(row["currently_active"])
-
-        return {row["user_id"]: UserPresenceState(**row) for row in rows}
-
-    def get_current_presence_token(self):
-        return self._presence_id_gen.get_current_token()
-
-    def allow_presence_visible(self, observed_localpart, observer_userid):
-        return self._simple_insert(
-            table="presence_allow_inbound",
-            values={
-                "observed_user_id": observed_localpart,
-                "observer_user_id": observer_userid,
-            },
-            desc="allow_presence_visible",
-            or_ignore=True,
-        )
-
-    def disallow_presence_visible(self, observed_localpart, observer_userid):
-        return self._simple_delete_one(
-            table="presence_allow_inbound",
-            keyvalues={
-                "observed_user_id": observed_localpart,
-                "observer_user_id": observer_userid,
-            },
-            desc="disallow_presence_visible",
-        )
diff --git a/synapse/storage/push_rule.py b/synapse/storage/push_rule.py
index c4e24edff2..f47cec0d86 100644
--- a/synapse/storage/push_rule.py
+++ b/synapse/storage/push_rule.py
@@ -14,704 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import abc
-import logging
-
-from canonicaljson import json
-
-from twisted.internet import defer
-
-from synapse.push.baserules import list_with_base_rules
-from synapse.storage.appservice import ApplicationServiceWorkerStore
-from synapse.storage.pusher import PusherWorkerStore
-from synapse.storage.receipts import ReceiptsWorkerStore
-from synapse.storage.roommember import RoomMemberWorkerStore
-from synapse.util.caches.descriptors import cachedInlineCallbacks, cachedList
-from synapse.util.caches.stream_change_cache import StreamChangeCache
-
-from ._base import SQLBaseStore
-
-logger = logging.getLogger(__name__)
-
-
-def _load_rules(rawrules, enabled_map):
-    ruleslist = []
-    for rawrule in rawrules:
-        rule = dict(rawrule)
-        rule["conditions"] = json.loads(rawrule["conditions"])
-        rule["actions"] = json.loads(rawrule["actions"])
-        ruleslist.append(rule)
-
-    # We're going to be mutating this a lot, so do a deep copy
-    rules = list(list_with_base_rules(ruleslist))
-
-    for i, rule in enumerate(rules):
-        rule_id = rule["rule_id"]
-        if rule_id in enabled_map:
-            if rule.get("enabled", True) != bool(enabled_map[rule_id]):
-                # Rules are cached across users.
-                rule = dict(rule)
-                rule["enabled"] = bool(enabled_map[rule_id])
-                rules[i] = rule
-
-    return rules
-
-
-class PushRulesWorkerStore(
-    ApplicationServiceWorkerStore,
-    ReceiptsWorkerStore,
-    PusherWorkerStore,
-    RoomMemberWorkerStore,
-    SQLBaseStore,
-):
-    """This is an abstract base class where subclasses must implement
-    `get_max_push_rules_stream_id` which can be called in the initializer.
-    """
-
-    # This ABCMeta metaclass ensures that we cannot be instantiated without
-    # the abstract methods being implemented.
-    __metaclass__ = abc.ABCMeta
-
-    def __init__(self, db_conn, hs):
-        super(PushRulesWorkerStore, self).__init__(db_conn, hs)
-
-        push_rules_prefill, push_rules_id = self._get_cache_dict(
-            db_conn,
-            "push_rules_stream",
-            entity_column="user_id",
-            stream_column="stream_id",
-            max_value=self.get_max_push_rules_stream_id(),
-        )
-
-        self.push_rules_stream_cache = StreamChangeCache(
-            "PushRulesStreamChangeCache",
-            push_rules_id,
-            prefilled_cache=push_rules_prefill,
-        )
-
-    @abc.abstractmethod
-    def get_max_push_rules_stream_id(self):
-        """Get the position of the push rules stream.
-
-        Returns:
-            int
-        """
-        raise NotImplementedError()
-
-    @cachedInlineCallbacks(max_entries=5000)
-    def get_push_rules_for_user(self, user_id):
-        rows = yield self._simple_select_list(
-            table="push_rules",
-            keyvalues={"user_name": user_id},
-            retcols=(
-                "user_name",
-                "rule_id",
-                "priority_class",
-                "priority",
-                "conditions",
-                "actions",
-            ),
-            desc="get_push_rules_enabled_for_user",
-        )
-
-        rows.sort(key=lambda row: (-int(row["priority_class"]), -int(row["priority"])))
-
-        enabled_map = yield self.get_push_rules_enabled_for_user(user_id)
-
-        rules = _load_rules(rows, enabled_map)
-
-        return rules
-
-    @cachedInlineCallbacks(max_entries=5000)
-    def get_push_rules_enabled_for_user(self, user_id):
-        results = yield self._simple_select_list(
-            table="push_rules_enable",
-            keyvalues={"user_name": user_id},
-            retcols=("user_name", "rule_id", "enabled"),
-            desc="get_push_rules_enabled_for_user",
-        )
-        return {r["rule_id"]: False if r["enabled"] == 0 else True for r in results}
-
-    def have_push_rules_changed_for_user(self, user_id, last_id):
-        if not self.push_rules_stream_cache.has_entity_changed(user_id, last_id):
-            return defer.succeed(False)
-        else:
-
-            def have_push_rules_changed_txn(txn):
-                sql = (
-                    "SELECT COUNT(stream_id) FROM push_rules_stream"
-                    " WHERE user_id = ? AND ? < stream_id"
-                )
-                txn.execute(sql, (user_id, last_id))
-                count, = txn.fetchone()
-                return bool(count)
-
-            return self.runInteraction(
-                "have_push_rules_changed", have_push_rules_changed_txn
-            )
-
-    @cachedList(
-        cached_method_name="get_push_rules_for_user",
-        list_name="user_ids",
-        num_args=1,
-        inlineCallbacks=True,
-    )
-    def bulk_get_push_rules(self, user_ids):
-        if not user_ids:
-            return {}
-
-        results = {user_id: [] for user_id in user_ids}
-
-        rows = yield self._simple_select_many_batch(
-            table="push_rules",
-            column="user_name",
-            iterable=user_ids,
-            retcols=("*",),
-            desc="bulk_get_push_rules",
-        )
-
-        rows.sort(key=lambda row: (-int(row["priority_class"]), -int(row["priority"])))
-
-        for row in rows:
-            results.setdefault(row["user_name"], []).append(row)
-
-        enabled_map_by_user = yield self.bulk_get_push_rules_enabled(user_ids)
-
-        for user_id, rules in results.items():
-            results[user_id] = _load_rules(rules, enabled_map_by_user.get(user_id, {}))
-
-        return results
-
-    @defer.inlineCallbacks
-    def copy_push_rule_from_room_to_room(self, new_room_id, user_id, rule):
-        """Copy a single push rule from one room to another for a specific user.
-
-        Args:
-            new_room_id (str): ID of the new room.
-            user_id (str): ID of user the push rule belongs to.
-            rule (Dict): A push rule.
-        """
-        # Create new rule id
-        rule_id_scope = "/".join(rule["rule_id"].split("/")[:-1])
-        new_rule_id = rule_id_scope + "/" + new_room_id
-
-        # Change room id in each condition
-        for condition in rule.get("conditions", []):
-            if condition.get("key") == "room_id":
-                condition["pattern"] = new_room_id
-
-        # Add the rule for the new room
-        yield self.add_push_rule(
-            user_id=user_id,
-            rule_id=new_rule_id,
-            priority_class=rule["priority_class"],
-            conditions=rule["conditions"],
-            actions=rule["actions"],
-        )
-
-    @defer.inlineCallbacks
-    def copy_push_rules_from_room_to_room_for_user(
-        self, old_room_id, new_room_id, user_id
-    ):
-        """Copy all of the push rules from one room to another for a specific
-        user.
-
-        Args:
-            old_room_id (str): ID of the old room.
-            new_room_id (str): ID of the new room.
-            user_id (str): ID of user to copy push rules for.
-        """
-        # Retrieve push rules for this user
-        user_push_rules = yield self.get_push_rules_for_user(user_id)
-
-        # Get rules relating to the old room and copy them to the new room
-        for rule in user_push_rules:
-            conditions = rule.get("conditions", [])
-            if any(
-                (c.get("key") == "room_id" and c.get("pattern") == old_room_id)
-                for c in conditions
-            ):
-                yield self.copy_push_rule_from_room_to_room(new_room_id, user_id, rule)
-
-    @defer.inlineCallbacks
-    def bulk_get_push_rules_for_room(self, event, context):
-        state_group = context.state_group
-        if not state_group:
-            # If state_group is None it means it has yet to be assigned a
-            # state group, i.e. we need to make sure that calls with a state_group
-            # of None don't hit previous cached calls with a None state_group.
-            # To do this we set the state_group to a new object as object() != object()
-            state_group = object()
-
-        current_state_ids = yield context.get_current_state_ids(self)
-        result = yield self._bulk_get_push_rules_for_room(
-            event.room_id, state_group, current_state_ids, event=event
-        )
-        return result
-
-    @cachedInlineCallbacks(num_args=2, cache_context=True)
-    def _bulk_get_push_rules_for_room(
-        self, room_id, state_group, current_state_ids, cache_context, event=None
-    ):
-        # We don't use `state_group`, its there so that we can cache based
-        # on it. However, its important that its never None, since two current_state's
-        # with a state_group of None are likely to be different.
-        # See bulk_get_push_rules_for_room for how we work around this.
-        assert state_group is not None
-
-        # We also will want to generate notifs for other people in the room so
-        # their unread countss are correct in the event stream, but to avoid
-        # generating them for bot / AS users etc, we only do so for people who've
-        # sent a read receipt into the room.
-
-        users_in_room = yield self._get_joined_users_from_context(
-            room_id,
-            state_group,
-            current_state_ids,
-            on_invalidate=cache_context.invalidate,
-            event=event,
-        )
-
-        # We ignore app service users for now. This is so that we don't fill
-        # up the `get_if_users_have_pushers` cache with AS entries that we
-        # know don't have pushers, nor even read receipts.
-        local_users_in_room = set(
-            u
-            for u in users_in_room
-            if self.hs.is_mine_id(u)
-            and not self.get_if_app_services_interested_in_user(u)
-        )
-
-        # users in the room who have pushers need to get push rules run because
-        # that's how their pushers work
-        if_users_with_pushers = yield self.get_if_users_have_pushers(
-            local_users_in_room, on_invalidate=cache_context.invalidate
-        )
-        user_ids = set(
-            uid for uid, have_pusher in if_users_with_pushers.items() if have_pusher
-        )
-
-        users_with_receipts = yield self.get_users_with_read_receipts_in_room(
-            room_id, on_invalidate=cache_context.invalidate
-        )
-
-        # any users with pushers must be ours: they have pushers
-        for uid in users_with_receipts:
-            if uid in local_users_in_room:
-                user_ids.add(uid)
-
-        rules_by_user = yield self.bulk_get_push_rules(
-            user_ids, on_invalidate=cache_context.invalidate
-        )
-
-        rules_by_user = {k: v for k, v in rules_by_user.items() if v is not None}
-
-        return rules_by_user
-
-    @cachedList(
-        cached_method_name="get_push_rules_enabled_for_user",
-        list_name="user_ids",
-        num_args=1,
-        inlineCallbacks=True,
-    )
-    def bulk_get_push_rules_enabled(self, user_ids):
-        if not user_ids:
-            return {}
-
-        results = {user_id: {} for user_id in user_ids}
-
-        rows = yield self._simple_select_many_batch(
-            table="push_rules_enable",
-            column="user_name",
-            iterable=user_ids,
-            retcols=("user_name", "rule_id", "enabled"),
-            desc="bulk_get_push_rules_enabled",
-        )
-        for row in rows:
-            enabled = bool(row["enabled"])
-            results.setdefault(row["user_name"], {})[row["rule_id"]] = enabled
-        return results
-
-
-class PushRuleStore(PushRulesWorkerStore):
-    @defer.inlineCallbacks
-    def add_push_rule(
-        self,
-        user_id,
-        rule_id,
-        priority_class,
-        conditions,
-        actions,
-        before=None,
-        after=None,
-    ):
-        conditions_json = json.dumps(conditions)
-        actions_json = json.dumps(actions)
-        with self._push_rules_stream_id_gen.get_next() as ids:
-            stream_id, event_stream_ordering = ids
-            if before or after:
-                yield self.runInteraction(
-                    "_add_push_rule_relative_txn",
-                    self._add_push_rule_relative_txn,
-                    stream_id,
-                    event_stream_ordering,
-                    user_id,
-                    rule_id,
-                    priority_class,
-                    conditions_json,
-                    actions_json,
-                    before,
-                    after,
-                )
-            else:
-                yield self.runInteraction(
-                    "_add_push_rule_highest_priority_txn",
-                    self._add_push_rule_highest_priority_txn,
-                    stream_id,
-                    event_stream_ordering,
-                    user_id,
-                    rule_id,
-                    priority_class,
-                    conditions_json,
-                    actions_json,
-                )
-
-    def _add_push_rule_relative_txn(
-        self,
-        txn,
-        stream_id,
-        event_stream_ordering,
-        user_id,
-        rule_id,
-        priority_class,
-        conditions_json,
-        actions_json,
-        before,
-        after,
-    ):
-        # Lock the table since otherwise we'll have annoying races between the
-        # SELECT here and the UPSERT below.
-        self.database_engine.lock_table(txn, "push_rules")
-
-        relative_to_rule = before or after
-
-        res = self._simple_select_one_txn(
-            txn,
-            table="push_rules",
-            keyvalues={"user_name": user_id, "rule_id": relative_to_rule},
-            retcols=["priority_class", "priority"],
-            allow_none=True,
-        )
-
-        if not res:
-            raise RuleNotFoundException(
-                "before/after rule not found: %s" % (relative_to_rule,)
-            )
-
-        base_priority_class = res["priority_class"]
-        base_rule_priority = res["priority"]
-
-        if base_priority_class != priority_class:
-            raise InconsistentRuleException(
-                "Given priority class does not match class of relative rule"
-            )
-
-        if before:
-            # Higher priority rules are executed first, So adding a rule before
-            # a rule means giving it a higher priority than that rule.
-            new_rule_priority = base_rule_priority + 1
-        else:
-            # We increment the priority of the existing rules to make space for
-            # the new rule. Therefore if we want this rule to appear after
-            # an existing rule we give it the priority of the existing rule,
-            # and then increment the priority of the existing rule.
-            new_rule_priority = base_rule_priority
-
-        sql = (
-            "UPDATE push_rules SET priority = priority + 1"
-            " WHERE user_name = ? AND priority_class = ? AND priority >= ?"
-        )
-
-        txn.execute(sql, (user_id, priority_class, new_rule_priority))
-
-        self._upsert_push_rule_txn(
-            txn,
-            stream_id,
-            event_stream_ordering,
-            user_id,
-            rule_id,
-            priority_class,
-            new_rule_priority,
-            conditions_json,
-            actions_json,
-        )
-
-    def _add_push_rule_highest_priority_txn(
-        self,
-        txn,
-        stream_id,
-        event_stream_ordering,
-        user_id,
-        rule_id,
-        priority_class,
-        conditions_json,
-        actions_json,
-    ):
-        # Lock the table since otherwise we'll have annoying races between the
-        # SELECT here and the UPSERT below.
-        self.database_engine.lock_table(txn, "push_rules")
-
-        # find the highest priority rule in that class
-        sql = (
-            "SELECT COUNT(*), MAX(priority) FROM push_rules"
-            " WHERE user_name = ? and priority_class = ?"
-        )
-        txn.execute(sql, (user_id, priority_class))
-        res = txn.fetchall()
-        (how_many, highest_prio) = res[0]
-
-        new_prio = 0
-        if how_many > 0:
-            new_prio = highest_prio + 1
-
-        self._upsert_push_rule_txn(
-            txn,
-            stream_id,
-            event_stream_ordering,
-            user_id,
-            rule_id,
-            priority_class,
-            new_prio,
-            conditions_json,
-            actions_json,
-        )
-
-    def _upsert_push_rule_txn(
-        self,
-        txn,
-        stream_id,
-        event_stream_ordering,
-        user_id,
-        rule_id,
-        priority_class,
-        priority,
-        conditions_json,
-        actions_json,
-        update_stream=True,
-    ):
-        """Specialised version of _simple_upsert_txn that picks a push_rule_id
-        using the _push_rule_id_gen if it needs to insert the rule. It assumes
-        that the "push_rules" table is locked"""
-
-        sql = (
-            "UPDATE push_rules"
-            " SET priority_class = ?, priority = ?, conditions = ?, actions = ?"
-            " WHERE user_name = ? AND rule_id = ?"
-        )
-
-        txn.execute(
-            sql,
-            (priority_class, priority, conditions_json, actions_json, user_id, rule_id),
-        )
-
-        if txn.rowcount == 0:
-            # We didn't update a row with the given rule_id so insert one
-            push_rule_id = self._push_rule_id_gen.get_next()
-
-            self._simple_insert_txn(
-                txn,
-                table="push_rules",
-                values={
-                    "id": push_rule_id,
-                    "user_name": user_id,
-                    "rule_id": rule_id,
-                    "priority_class": priority_class,
-                    "priority": priority,
-                    "conditions": conditions_json,
-                    "actions": actions_json,
-                },
-            )
-
-        if update_stream:
-            self._insert_push_rules_update_txn(
-                txn,
-                stream_id,
-                event_stream_ordering,
-                user_id,
-                rule_id,
-                op="ADD",
-                data={
-                    "priority_class": priority_class,
-                    "priority": priority,
-                    "conditions": conditions_json,
-                    "actions": actions_json,
-                },
-            )
-
-    @defer.inlineCallbacks
-    def delete_push_rule(self, user_id, rule_id):
-        """
-        Delete a push rule. Args specify the row to be deleted and can be
-        any of the columns in the push_rule table, but below are the
-        standard ones
-
-        Args:
-            user_id (str): The matrix ID of the push rule owner
-            rule_id (str): The rule_id of the rule to be deleted
-        """
-
-        def delete_push_rule_txn(txn, stream_id, event_stream_ordering):
-            self._simple_delete_one_txn(
-                txn, "push_rules", {"user_name": user_id, "rule_id": rule_id}
-            )
-
-            self._insert_push_rules_update_txn(
-                txn, stream_id, event_stream_ordering, user_id, rule_id, op="DELETE"
-            )
-
-        with self._push_rules_stream_id_gen.get_next() as ids:
-            stream_id, event_stream_ordering = ids
-            yield self.runInteraction(
-                "delete_push_rule",
-                delete_push_rule_txn,
-                stream_id,
-                event_stream_ordering,
-            )
-
-    @defer.inlineCallbacks
-    def set_push_rule_enabled(self, user_id, rule_id, enabled):
-        with self._push_rules_stream_id_gen.get_next() as ids:
-            stream_id, event_stream_ordering = ids
-            yield self.runInteraction(
-                "_set_push_rule_enabled_txn",
-                self._set_push_rule_enabled_txn,
-                stream_id,
-                event_stream_ordering,
-                user_id,
-                rule_id,
-                enabled,
-            )
-
-    def _set_push_rule_enabled_txn(
-        self, txn, stream_id, event_stream_ordering, user_id, rule_id, enabled
-    ):
-        new_id = self._push_rules_enable_id_gen.get_next()
-        self._simple_upsert_txn(
-            txn,
-            "push_rules_enable",
-            {"user_name": user_id, "rule_id": rule_id},
-            {"enabled": 1 if enabled else 0},
-            {"id": new_id},
-        )
-
-        self._insert_push_rules_update_txn(
-            txn,
-            stream_id,
-            event_stream_ordering,
-            user_id,
-            rule_id,
-            op="ENABLE" if enabled else "DISABLE",
-        )
-
-    @defer.inlineCallbacks
-    def set_push_rule_actions(self, user_id, rule_id, actions, is_default_rule):
-        actions_json = json.dumps(actions)
-
-        def set_push_rule_actions_txn(txn, stream_id, event_stream_ordering):
-            if is_default_rule:
-                # Add a dummy rule to the rules table with the user specified
-                # actions.
-                priority_class = -1
-                priority = 1
-                self._upsert_push_rule_txn(
-                    txn,
-                    stream_id,
-                    event_stream_ordering,
-                    user_id,
-                    rule_id,
-                    priority_class,
-                    priority,
-                    "[]",
-                    actions_json,
-                    update_stream=False,
-                )
-            else:
-                self._simple_update_one_txn(
-                    txn,
-                    "push_rules",
-                    {"user_name": user_id, "rule_id": rule_id},
-                    {"actions": actions_json},
-                )
-
-            self._insert_push_rules_update_txn(
-                txn,
-                stream_id,
-                event_stream_ordering,
-                user_id,
-                rule_id,
-                op="ACTIONS",
-                data={"actions": actions_json},
-            )
-
-        with self._push_rules_stream_id_gen.get_next() as ids:
-            stream_id, event_stream_ordering = ids
-            yield self.runInteraction(
-                "set_push_rule_actions",
-                set_push_rule_actions_txn,
-                stream_id,
-                event_stream_ordering,
-            )
-
-    def _insert_push_rules_update_txn(
-        self, txn, stream_id, event_stream_ordering, user_id, rule_id, op, data=None
-    ):
-        values = {
-            "stream_id": stream_id,
-            "event_stream_ordering": event_stream_ordering,
-            "user_id": user_id,
-            "rule_id": rule_id,
-            "op": op,
-        }
-        if data is not None:
-            values.update(data)
-
-        self._simple_insert_txn(txn, "push_rules_stream", values=values)
-
-        txn.call_after(self.get_push_rules_for_user.invalidate, (user_id,))
-        txn.call_after(self.get_push_rules_enabled_for_user.invalidate, (user_id,))
-        txn.call_after(
-            self.push_rules_stream_cache.entity_has_changed, user_id, stream_id
-        )
-
-    def get_all_push_rule_updates(self, last_id, current_id, limit):
-        """Get all the push rules changes that have happend on the server"""
-        if last_id == current_id:
-            return defer.succeed([])
-
-        def get_all_push_rule_updates_txn(txn):
-            sql = (
-                "SELECT stream_id, event_stream_ordering, user_id, rule_id,"
-                " op, priority_class, priority, conditions, actions"
-                " FROM push_rules_stream"
-                " WHERE ? < stream_id AND stream_id <= ?"
-                " ORDER BY stream_id ASC LIMIT ?"
-            )
-            txn.execute(sql, (last_id, current_id, limit))
-            return txn.fetchall()
-
-        return self.runInteraction(
-            "get_all_push_rule_updates", get_all_push_rule_updates_txn
-        )
-
-    def get_push_rules_stream_token(self):
-        """Get the position of the push rules stream.
-        Returns a pair of a stream id for the push_rules stream and the
-        room stream ordering it corresponds to."""
-        return self._push_rules_stream_id_gen.get_current_token()
-
-    def get_max_push_rules_stream_id(self):
-        return self.get_push_rules_stream_token()[0]
-
 
 class RuleNotFoundException(Exception):
     pass
diff --git a/synapse/storage/relations.py b/synapse/storage/relations.py
index fcb5f2f23a..d471ec9860 100644
--- a/synapse/storage/relations.py
+++ b/synapse/storage/relations.py
@@ -17,11 +17,7 @@ import logging
 
 import attr
 
-from synapse.api.constants import RelationTypes
 from synapse.api.errors import SynapseError
-from synapse.storage._base import SQLBaseStore
-from synapse.storage.stream import generate_pagination_where_clause
-from synapse.util.caches.descriptors import cached, cachedInlineCallbacks
 
 logger = logging.getLogger(__name__)
 
@@ -113,358 +109,3 @@ class AggregationPaginationToken(object):
 
     def as_tuple(self):
         return attr.astuple(self)
-
-
-class RelationsWorkerStore(SQLBaseStore):
-    @cached(tree=True)
-    def get_relations_for_event(
-        self,
-        event_id,
-        relation_type=None,
-        event_type=None,
-        aggregation_key=None,
-        limit=5,
-        direction="b",
-        from_token=None,
-        to_token=None,
-    ):
-        """Get a list of relations for an event, ordered by topological ordering.
-
-        Args:
-            event_id (str): Fetch events that relate to this event ID.
-            relation_type (str|None): Only fetch events with this relation
-                type, if given.
-            event_type (str|None): Only fetch events with this event type, if
-                given.
-            aggregation_key (str|None): Only fetch events with this aggregation
-                key, if given.
-            limit (int): Only fetch the most recent `limit` events.
-            direction (str): Whether to fetch the most recent first (`"b"`) or
-                the oldest first (`"f"`).
-            from_token (RelationPaginationToken|None): Fetch rows from the given
-                token, or from the start if None.
-            to_token (RelationPaginationToken|None): Fetch rows up to the given
-                token, or up to the end if None.
-
-        Returns:
-            Deferred[PaginationChunk]: List of event IDs that match relations
-            requested. The rows are of the form `{"event_id": "..."}`.
-        """
-
-        where_clause = ["relates_to_id = ?"]
-        where_args = [event_id]
-
-        if relation_type is not None:
-            where_clause.append("relation_type = ?")
-            where_args.append(relation_type)
-
-        if event_type is not None:
-            where_clause.append("type = ?")
-            where_args.append(event_type)
-
-        if aggregation_key:
-            where_clause.append("aggregation_key = ?")
-            where_args.append(aggregation_key)
-
-        pagination_clause = generate_pagination_where_clause(
-            direction=direction,
-            column_names=("topological_ordering", "stream_ordering"),
-            from_token=attr.astuple(from_token) if from_token else None,
-            to_token=attr.astuple(to_token) if to_token else None,
-            engine=self.database_engine,
-        )
-
-        if pagination_clause:
-            where_clause.append(pagination_clause)
-
-        if direction == "b":
-            order = "DESC"
-        else:
-            order = "ASC"
-
-        sql = """
-            SELECT event_id, topological_ordering, stream_ordering
-            FROM event_relations
-            INNER JOIN events USING (event_id)
-            WHERE %s
-            ORDER BY topological_ordering %s, stream_ordering %s
-            LIMIT ?
-        """ % (
-            " AND ".join(where_clause),
-            order,
-            order,
-        )
-
-        def _get_recent_references_for_event_txn(txn):
-            txn.execute(sql, where_args + [limit + 1])
-
-            last_topo_id = None
-            last_stream_id = None
-            events = []
-            for row in txn:
-                events.append({"event_id": row[0]})
-                last_topo_id = row[1]
-                last_stream_id = row[2]
-
-            next_batch = None
-            if len(events) > limit and last_topo_id and last_stream_id:
-                next_batch = RelationPaginationToken(last_topo_id, last_stream_id)
-
-            return PaginationChunk(
-                chunk=list(events[:limit]), next_batch=next_batch, prev_batch=from_token
-            )
-
-        return self.runInteraction(
-            "get_recent_references_for_event", _get_recent_references_for_event_txn
-        )
-
-    @cached(tree=True)
-    def get_aggregation_groups_for_event(
-        self,
-        event_id,
-        event_type=None,
-        limit=5,
-        direction="b",
-        from_token=None,
-        to_token=None,
-    ):
-        """Get a list of annotations on the event, grouped by event type and
-        aggregation key, sorted by count.
-
-        This is used e.g. to get the what and how many reactions have happend
-        on an event.
-
-        Args:
-            event_id (str): Fetch events that relate to this event ID.
-            event_type (str|None): Only fetch events with this event type, if
-                given.
-            limit (int): Only fetch the `limit` groups.
-            direction (str): Whether to fetch the highest count first (`"b"`) or
-                the lowest count first (`"f"`).
-            from_token (AggregationPaginationToken|None): Fetch rows from the
-                given token, or from the start if None.
-            to_token (AggregationPaginationToken|None): Fetch rows up to the
-                given token, or up to the end if None.
-
-
-        Returns:
-            Deferred[PaginationChunk]: List of groups of annotations that
-            match. Each row is a dict with `type`, `key` and `count` fields.
-        """
-
-        where_clause = ["relates_to_id = ?", "relation_type = ?"]
-        where_args = [event_id, RelationTypes.ANNOTATION]
-
-        if event_type:
-            where_clause.append("type = ?")
-            where_args.append(event_type)
-
-        having_clause = generate_pagination_where_clause(
-            direction=direction,
-            column_names=("COUNT(*)", "MAX(stream_ordering)"),
-            from_token=attr.astuple(from_token) if from_token else None,
-            to_token=attr.astuple(to_token) if to_token else None,
-            engine=self.database_engine,
-        )
-
-        if direction == "b":
-            order = "DESC"
-        else:
-            order = "ASC"
-
-        if having_clause:
-            having_clause = "HAVING " + having_clause
-        else:
-            having_clause = ""
-
-        sql = """
-            SELECT type, aggregation_key, COUNT(DISTINCT sender), MAX(stream_ordering)
-            FROM event_relations
-            INNER JOIN events USING (event_id)
-            WHERE {where_clause}
-            GROUP BY relation_type, type, aggregation_key
-            {having_clause}
-            ORDER BY COUNT(*) {order}, MAX(stream_ordering) {order}
-            LIMIT ?
-        """.format(
-            where_clause=" AND ".join(where_clause),
-            order=order,
-            having_clause=having_clause,
-        )
-
-        def _get_aggregation_groups_for_event_txn(txn):
-            txn.execute(sql, where_args + [limit + 1])
-
-            next_batch = None
-            events = []
-            for row in txn:
-                events.append({"type": row[0], "key": row[1], "count": row[2]})
-                next_batch = AggregationPaginationToken(row[2], row[3])
-
-            if len(events) <= limit:
-                next_batch = None
-
-            return PaginationChunk(
-                chunk=list(events[:limit]), next_batch=next_batch, prev_batch=from_token
-            )
-
-        return self.runInteraction(
-            "get_aggregation_groups_for_event", _get_aggregation_groups_for_event_txn
-        )
-
-    @cachedInlineCallbacks()
-    def get_applicable_edit(self, event_id):
-        """Get the most recent edit (if any) that has happened for the given
-        event.
-
-        Correctly handles checking whether edits were allowed to happen.
-
-        Args:
-            event_id (str): The original event ID
-
-        Returns:
-            Deferred[EventBase|None]: Returns the most recent edit, if any.
-        """
-
-        # We only allow edits for `m.room.message` events that have the same sender
-        # and event type. We can't assert these things during regular event auth so
-        # we have to do the checks post hoc.
-
-        # Fetches latest edit that has the same type and sender as the
-        # original, and is an `m.room.message`.
-        sql = """
-            SELECT edit.event_id FROM events AS edit
-            INNER JOIN event_relations USING (event_id)
-            INNER JOIN events AS original ON
-                original.event_id = relates_to_id
-                AND edit.type = original.type
-                AND edit.sender = original.sender
-            WHERE
-                relates_to_id = ?
-                AND relation_type = ?
-                AND edit.type = 'm.room.message'
-            ORDER by edit.origin_server_ts DESC, edit.event_id DESC
-            LIMIT 1
-        """
-
-        def _get_applicable_edit_txn(txn):
-            txn.execute(sql, (event_id, RelationTypes.REPLACE))
-            row = txn.fetchone()
-            if row:
-                return row[0]
-
-        edit_id = yield self.runInteraction(
-            "get_applicable_edit", _get_applicable_edit_txn
-        )
-
-        if not edit_id:
-            return
-
-        edit_event = yield self.get_event(edit_id, allow_none=True)
-        return edit_event
-
-    def has_user_annotated_event(self, parent_id, event_type, aggregation_key, sender):
-        """Check if a user has already annotated an event with the same key
-        (e.g. already liked an event).
-
-        Args:
-            parent_id (str): The event being annotated
-            event_type (str): The event type of the annotation
-            aggregation_key (str): The aggregation key of the annotation
-            sender (str): The sender of the annotation
-
-        Returns:
-            Deferred[bool]
-        """
-
-        sql = """
-            SELECT 1 FROM event_relations
-            INNER JOIN events USING (event_id)
-            WHERE
-                relates_to_id = ?
-                AND relation_type = ?
-                AND type = ?
-                AND sender = ?
-                AND aggregation_key = ?
-            LIMIT 1;
-        """
-
-        def _get_if_user_has_annotated_event(txn):
-            txn.execute(
-                sql,
-                (
-                    parent_id,
-                    RelationTypes.ANNOTATION,
-                    event_type,
-                    sender,
-                    aggregation_key,
-                ),
-            )
-
-            return bool(txn.fetchone())
-
-        return self.runInteraction(
-            "get_if_user_has_annotated_event", _get_if_user_has_annotated_event
-        )
-
-
-class RelationsStore(RelationsWorkerStore):
-    def _handle_event_relations(self, txn, event):
-        """Handles inserting relation data during peristence of events
-
-        Args:
-            txn
-            event (EventBase)
-        """
-        relation = event.content.get("m.relates_to")
-        if not relation:
-            # No relations
-            return
-
-        rel_type = relation.get("rel_type")
-        if rel_type not in (
-            RelationTypes.ANNOTATION,
-            RelationTypes.REFERENCE,
-            RelationTypes.REPLACE,
-        ):
-            # Unknown relation type
-            return
-
-        parent_id = relation.get("event_id")
-        if not parent_id:
-            # Invalid relation
-            return
-
-        aggregation_key = relation.get("key")
-
-        self._simple_insert_txn(
-            txn,
-            table="event_relations",
-            values={
-                "event_id": event.event_id,
-                "relates_to_id": parent_id,
-                "relation_type": rel_type,
-                "aggregation_key": aggregation_key,
-            },
-        )
-
-        txn.call_after(self.get_relations_for_event.invalidate_many, (parent_id,))
-        txn.call_after(
-            self.get_aggregation_groups_for_event.invalidate_many, (parent_id,)
-        )
-
-        if rel_type == RelationTypes.REPLACE:
-            txn.call_after(self.get_applicable_edit.invalidate, (parent_id,))
-
-    def _handle_redaction(self, txn, redacted_event_id):
-        """Handles receiving a redaction and checking whether we need to remove
-        any redacted relations from the database.
-
-        Args:
-            txn
-            redacted_event_id (str): The event that was redacted.
-        """
-
-        self._simple_delete_txn(
-            txn, table="event_relations", keyvalues={"event_id": redacted_event_id}
-        )
diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py
index ff63487823..8c4a83a840 100644
--- a/synapse/storage/roommember.py
+++ b/synapse/storage/roommember.py
@@ -17,26 +17,6 @@
 import logging
 from collections import namedtuple
 
-from six import iteritems, itervalues
-
-from canonicaljson import json
-
-from twisted.internet import defer
-
-from synapse.api.constants import EventTypes, Membership
-from synapse.metrics import LaterGauge
-from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.storage._base import LoggingTransaction, make_in_list_sql_clause
-from synapse.storage.background_updates import BackgroundUpdateStore
-from synapse.storage.engines import Sqlite3Engine
-from synapse.storage.events_worker import EventsWorkerStore
-from synapse.types import get_domain_from_id
-from synapse.util.async_helpers import Linearizer
-from synapse.util.caches import intern_string
-from synapse.util.caches.descriptors import cached, cachedInlineCallbacks, cachedList
-from synapse.util.metrics import Measure
-from synapse.util.stringutils import to_ascii
-
 logger = logging.getLogger(__name__)
 
 
@@ -57,1102 +37,3 @@ ProfileInfo = namedtuple("ProfileInfo", ("avatar_url", "display_name"))
 # a given membership type, suitable for use in calculating heroes for a room.
 # "count" points to the total numberr of users of a given membership type.
 MemberSummary = namedtuple("MemberSummary", ("members", "count"))
-
-_MEMBERSHIP_PROFILE_UPDATE_NAME = "room_membership_profile_update"
-_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME = "current_state_events_membership"
-
-
-class RoomMemberWorkerStore(EventsWorkerStore):
-    def __init__(self, db_conn, hs):
-        super(RoomMemberWorkerStore, self).__init__(db_conn, hs)
-
-        # Is the current_state_events.membership up to date? Or is the
-        # background update still running?
-        self._current_state_events_membership_up_to_date = False
-
-        txn = LoggingTransaction(
-            db_conn.cursor(),
-            name="_check_safe_current_state_events_membership_updated",
-            database_engine=self.database_engine,
-        )
-        self._check_safe_current_state_events_membership_updated_txn(txn)
-        txn.close()
-
-        if self.hs.config.metrics_flags.known_servers:
-            self._known_servers_count = 1
-            self.hs.get_clock().looping_call(
-                run_as_background_process,
-                60 * 1000,
-                "_count_known_servers",
-                self._count_known_servers,
-            )
-            self.hs.get_clock().call_later(
-                1000,
-                run_as_background_process,
-                "_count_known_servers",
-                self._count_known_servers,
-            )
-            LaterGauge(
-                "synapse_federation_known_servers",
-                "",
-                [],
-                lambda: self._known_servers_count,
-            )
-
-    @defer.inlineCallbacks
-    def _count_known_servers(self):
-        """
-        Count the servers that this server knows about.
-
-        The statistic is stored on the class for the
-        `synapse_federation_known_servers` LaterGauge to collect.
-        """
-
-        def _transact(txn):
-            if isinstance(self.database_engine, Sqlite3Engine):
-                query = """
-                    SELECT COUNT(DISTINCT substr(out.user_id, pos+1))
-                    FROM (
-                        SELECT rm.user_id as user_id, instr(rm.user_id, ':')
-                            AS pos FROM room_memberships as rm
-                        INNER JOIN current_state_events as c ON rm.event_id = c.event_id
-                        WHERE c.type = 'm.room.member'
-                    ) as out
-                """
-            else:
-                query = """
-                    SELECT COUNT(DISTINCT split_part(state_key, ':', 2))
-                    FROM current_state_events
-                    WHERE type = 'm.room.member' AND membership = 'join';
-                """
-            txn.execute(query)
-            return list(txn)[0][0]
-
-        count = yield self.runInteraction("get_known_servers", _transact)
-
-        # We always know about ourselves, even if we have nothing in
-        # room_memberships (for example, the server is new).
-        self._known_servers_count = max([count, 1])
-        return self._known_servers_count
-
-    def _check_safe_current_state_events_membership_updated_txn(self, txn):
-        """Checks if it is safe to assume the new current_state_events
-        membership column is up to date
-        """
-
-        pending_update = self._simple_select_one_txn(
-            txn,
-            table="background_updates",
-            keyvalues={"update_name": _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME},
-            retcols=["update_name"],
-            allow_none=True,
-        )
-
-        self._current_state_events_membership_up_to_date = not pending_update
-
-        # If the update is still running, reschedule to run.
-        if pending_update:
-            self._clock.call_later(
-                15.0,
-                run_as_background_process,
-                "_check_safe_current_state_events_membership_updated",
-                self.runInteraction,
-                "_check_safe_current_state_events_membership_updated",
-                self._check_safe_current_state_events_membership_updated_txn,
-            )
-
-    @cachedInlineCallbacks(max_entries=100000, iterable=True, cache_context=True)
-    def get_hosts_in_room(self, room_id, cache_context):
-        """Returns the set of all hosts currently in the room
-        """
-        user_ids = yield self.get_users_in_room(
-            room_id, on_invalidate=cache_context.invalidate
-        )
-        hosts = frozenset(get_domain_from_id(user_id) for user_id in user_ids)
-        return hosts
-
-    @cached(max_entries=100000, iterable=True)
-    def get_users_in_room(self, room_id):
-        return self.runInteraction(
-            "get_users_in_room", self.get_users_in_room_txn, room_id
-        )
-
-    def get_users_in_room_txn(self, txn, room_id):
-        # If we can assume current_state_events.membership is up to date
-        # then we can avoid a join, which is a Very Good Thing given how
-        # frequently this function gets called.
-        if self._current_state_events_membership_up_to_date:
-            sql = """
-                SELECT state_key FROM current_state_events
-                WHERE type = 'm.room.member' AND room_id = ? AND membership = ?
-            """
-        else:
-            sql = """
-                SELECT state_key FROM room_memberships as m
-                INNER JOIN current_state_events as c
-                ON m.event_id = c.event_id
-                AND m.room_id = c.room_id
-                AND m.user_id = c.state_key
-                WHERE c.type = 'm.room.member' AND c.room_id = ? AND m.membership = ?
-            """
-
-        txn.execute(sql, (room_id, Membership.JOIN))
-        return [to_ascii(r[0]) for r in txn]
-
-    @cached(max_entries=100000)
-    def get_room_summary(self, room_id):
-        """ Get the details of a room roughly suitable for use by the room
-        summary extension to /sync. Useful when lazy loading room members.
-        Args:
-            room_id (str): The room ID to query
-        Returns:
-            Deferred[dict[str, MemberSummary]:
-                dict of membership states, pointing to a MemberSummary named tuple.
-        """
-
-        def _get_room_summary_txn(txn):
-            # first get counts.
-            # We do this all in one transaction to keep the cache small.
-            # FIXME: get rid of this when we have room_stats
-
-            # If we can assume current_state_events.membership is up to date
-            # then we can avoid a join, which is a Very Good Thing given how
-            # frequently this function gets called.
-            if self._current_state_events_membership_up_to_date:
-                # Note, rejected events will have a null membership field, so
-                # we we manually filter them out.
-                sql = """
-                    SELECT count(*), membership FROM current_state_events
-                    WHERE type = 'm.room.member' AND room_id = ?
-                        AND membership IS NOT NULL
-                    GROUP BY membership
-                """
-            else:
-                sql = """
-                    SELECT count(*), m.membership FROM room_memberships as m
-                    INNER JOIN current_state_events as c
-                    ON m.event_id = c.event_id
-                    AND m.room_id = c.room_id
-                    AND m.user_id = c.state_key
-                    WHERE c.type = 'm.room.member' AND c.room_id = ?
-                    GROUP BY m.membership
-                """
-
-            txn.execute(sql, (room_id,))
-            res = {}
-            for count, membership in txn:
-                summary = res.setdefault(to_ascii(membership), MemberSummary([], count))
-
-            # we order by membership and then fairly arbitrarily by event_id so
-            # heroes are consistent
-            if self._current_state_events_membership_up_to_date:
-                # Note, rejected events will have a null membership field, so
-                # we we manually filter them out.
-                sql = """
-                    SELECT state_key, membership, event_id
-                    FROM current_state_events
-                    WHERE type = 'm.room.member' AND room_id = ?
-                        AND membership IS NOT NULL
-                    ORDER BY
-                        CASE membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
-                        event_id ASC
-                    LIMIT ?
-                """
-            else:
-                sql = """
-                    SELECT c.state_key, m.membership, c.event_id
-                    FROM room_memberships as m
-                    INNER JOIN current_state_events as c USING (room_id, event_id)
-                    WHERE c.type = 'm.room.member' AND c.room_id = ?
-                    ORDER BY
-                        CASE m.membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
-                        c.event_id ASC
-                    LIMIT ?
-                """
-
-            # 6 is 5 (number of heroes) plus 1, in case one of them is the calling user.
-            txn.execute(sql, (room_id, Membership.JOIN, Membership.INVITE, 6))
-            for user_id, membership, event_id in txn:
-                summary = res[to_ascii(membership)]
-                # we will always have a summary for this membership type at this
-                # point given the summary currently contains the counts.
-                members = summary.members
-                members.append((to_ascii(user_id), to_ascii(event_id)))
-
-            return res
-
-        return self.runInteraction("get_room_summary", _get_room_summary_txn)
-
-    def _get_user_counts_in_room_txn(self, txn, room_id):
-        """
-        Get the user count in a room by membership.
-
-        Args:
-            room_id (str)
-            membership (Membership)
-
-        Returns:
-            Deferred[int]
-        """
-        sql = """
-        SELECT m.membership, count(*) FROM room_memberships as m
-            INNER JOIN current_state_events as c USING(event_id)
-            WHERE c.type = 'm.room.member' AND c.room_id = ?
-            GROUP BY m.membership
-        """
-
-        txn.execute(sql, (room_id,))
-        return {row[0]: row[1] for row in txn}
-
-    @cached()
-    def get_invited_rooms_for_user(self, user_id):
-        """ Get all the rooms the user is invited to
-        Args:
-            user_id (str): The user ID.
-        Returns:
-            A deferred list of RoomsForUser.
-        """
-
-        return self.get_rooms_for_user_where_membership_is(user_id, [Membership.INVITE])
-
-    @defer.inlineCallbacks
-    def get_invite_for_user_in_room(self, user_id, room_id):
-        """Gets the invite for the given user and room
-
-        Args:
-            user_id (str)
-            room_id (str)
-
-        Returns:
-            Deferred: Resolves to either a RoomsForUser or None if no invite was
-                found.
-        """
-        invites = yield self.get_invited_rooms_for_user(user_id)
-        for invite in invites:
-            if invite.room_id == room_id:
-                return invite
-        return None
-
-    @defer.inlineCallbacks
-    def get_rooms_for_user_where_membership_is(self, user_id, membership_list):
-        """ Get all the rooms for this user where the membership for this user
-        matches one in the membership list.
-
-        Filters out forgotten rooms.
-
-        Args:
-            user_id (str): The user ID.
-            membership_list (list): A list of synapse.api.constants.Membership
-            values which the user must be in.
-
-        Returns:
-            Deferred[list[RoomsForUser]]
-        """
-        if not membership_list:
-            return defer.succeed(None)
-
-        rooms = yield self.runInteraction(
-            "get_rooms_for_user_where_membership_is",
-            self._get_rooms_for_user_where_membership_is_txn,
-            user_id,
-            membership_list,
-        )
-
-        # Now we filter out forgotten rooms
-        forgotten_rooms = yield self.get_forgotten_rooms_for_user(user_id)
-        return [room for room in rooms if room.room_id not in forgotten_rooms]
-
-    def _get_rooms_for_user_where_membership_is_txn(
-        self, txn, user_id, membership_list
-    ):
-
-        do_invite = Membership.INVITE in membership_list
-        membership_list = [m for m in membership_list if m != Membership.INVITE]
-
-        results = []
-        if membership_list:
-            if self._current_state_events_membership_up_to_date:
-                clause, args = make_in_list_sql_clause(
-                    self.database_engine, "c.membership", membership_list
-                )
-                sql = """
-                    SELECT room_id, e.sender, c.membership, event_id, e.stream_ordering
-                    FROM current_state_events AS c
-                    INNER JOIN events AS e USING (room_id, event_id)
-                    WHERE
-                        c.type = 'm.room.member'
-                        AND state_key = ?
-                        AND %s
-                """ % (
-                    clause,
-                )
-            else:
-                clause, args = make_in_list_sql_clause(
-                    self.database_engine, "m.membership", membership_list
-                )
-                sql = """
-                    SELECT room_id, e.sender, m.membership, event_id, e.stream_ordering
-                    FROM current_state_events AS c
-                    INNER JOIN room_memberships AS m USING (room_id, event_id)
-                    INNER JOIN events AS e USING (room_id, event_id)
-                    WHERE
-                        c.type = 'm.room.member'
-                        AND state_key = ?
-                        AND %s
-                """ % (
-                    clause,
-                )
-
-            txn.execute(sql, (user_id, *args))
-            results = [RoomsForUser(**r) for r in self.cursor_to_dict(txn)]
-
-        if do_invite:
-            sql = (
-                "SELECT i.room_id, inviter, i.event_id, e.stream_ordering"
-                " FROM local_invites as i"
-                " INNER JOIN events as e USING (event_id)"
-                " WHERE invitee = ? AND locally_rejected is NULL"
-                " AND replaced_by is NULL"
-            )
-
-            txn.execute(sql, (user_id,))
-            results.extend(
-                RoomsForUser(
-                    room_id=r["room_id"],
-                    sender=r["inviter"],
-                    event_id=r["event_id"],
-                    stream_ordering=r["stream_ordering"],
-                    membership=Membership.INVITE,
-                )
-                for r in self.cursor_to_dict(txn)
-            )
-
-        return results
-
-    @cachedInlineCallbacks(max_entries=500000, iterable=True)
-    def get_rooms_for_user_with_stream_ordering(self, user_id):
-        """Returns a set of room_ids the user is currently joined to
-
-        Args:
-            user_id (str)
-
-        Returns:
-            Deferred[frozenset[GetRoomsForUserWithStreamOrdering]]: Returns
-            the rooms the user is in currently, along with the stream ordering
-            of the most recent join for that user and room.
-        """
-        rooms = yield self.get_rooms_for_user_where_membership_is(
-            user_id, membership_list=[Membership.JOIN]
-        )
-        return frozenset(
-            GetRoomsForUserWithStreamOrdering(r.room_id, r.stream_ordering)
-            for r in rooms
-        )
-
-    @defer.inlineCallbacks
-    def get_rooms_for_user(self, user_id, on_invalidate=None):
-        """Returns a set of room_ids the user is currently joined to
-        """
-        rooms = yield self.get_rooms_for_user_with_stream_ordering(
-            user_id, on_invalidate=on_invalidate
-        )
-        return frozenset(r.room_id for r in rooms)
-
-    @cachedInlineCallbacks(max_entries=500000, cache_context=True, iterable=True)
-    def get_users_who_share_room_with_user(self, user_id, cache_context):
-        """Returns the set of users who share a room with `user_id`
-        """
-        room_ids = yield self.get_rooms_for_user(
-            user_id, on_invalidate=cache_context.invalidate
-        )
-
-        user_who_share_room = set()
-        for room_id in room_ids:
-            user_ids = yield self.get_users_in_room(
-                room_id, on_invalidate=cache_context.invalidate
-            )
-            user_who_share_room.update(user_ids)
-
-        return user_who_share_room
-
-    @defer.inlineCallbacks
-    def get_joined_users_from_context(self, event, context):
-        state_group = context.state_group
-        if not state_group:
-            # If state_group is None it means it has yet to be assigned a
-            # state group, i.e. we need to make sure that calls with a state_group
-            # of None don't hit previous cached calls with a None state_group.
-            # To do this we set the state_group to a new object as object() != object()
-            state_group = object()
-
-        current_state_ids = yield context.get_current_state_ids(self)
-        result = yield self._get_joined_users_from_context(
-            event.room_id, state_group, current_state_ids, event=event, context=context
-        )
-        return result
-
-    @defer.inlineCallbacks
-    def get_joined_users_from_state(self, room_id, state_entry):
-        state_group = state_entry.state_group
-        if not state_group:
-            # If state_group is None it means it has yet to be assigned a
-            # state group, i.e. we need to make sure that calls with a state_group
-            # of None don't hit previous cached calls with a None state_group.
-            # To do this we set the state_group to a new object as object() != object()
-            state_group = object()
-
-        with Measure(self._clock, "get_joined_users_from_state"):
-            return (
-                yield self._get_joined_users_from_context(
-                    room_id, state_group, state_entry.state, context=state_entry
-                )
-            )
-
-    @cachedInlineCallbacks(
-        num_args=2, cache_context=True, iterable=True, max_entries=100000
-    )
-    def _get_joined_users_from_context(
-        self,
-        room_id,
-        state_group,
-        current_state_ids,
-        cache_context,
-        event=None,
-        context=None,
-    ):
-        # We don't use `state_group`, it's there so that we can cache based
-        # on it. However, it's important that it's never None, since two current_states
-        # with a state_group of None are likely to be different.
-        # See bulk_get_push_rules_for_room for how we work around this.
-        assert state_group is not None
-
-        users_in_room = {}
-        member_event_ids = [
-            e_id
-            for key, e_id in iteritems(current_state_ids)
-            if key[0] == EventTypes.Member
-        ]
-
-        if context is not None:
-            # If we have a context with a delta from a previous state group,
-            # check if we also have the result from the previous group in cache.
-            # If we do then we can reuse that result and simply update it with
-            # any membership changes in `delta_ids`
-            if context.prev_group and context.delta_ids:
-                prev_res = self._get_joined_users_from_context.cache.get(
-                    (room_id, context.prev_group), None
-                )
-                if prev_res and isinstance(prev_res, dict):
-                    users_in_room = dict(prev_res)
-                    member_event_ids = [
-                        e_id
-                        for key, e_id in iteritems(context.delta_ids)
-                        if key[0] == EventTypes.Member
-                    ]
-                    for etype, state_key in context.delta_ids:
-                        users_in_room.pop(state_key, None)
-
-        # We check if we have any of the member event ids in the event cache
-        # before we ask the DB
-
-        # We don't update the event cache hit ratio as it completely throws off
-        # the hit ratio counts. After all, we don't populate the cache if we
-        # miss it here
-        event_map = self._get_events_from_cache(
-            member_event_ids, allow_rejected=False, update_metrics=False
-        )
-
-        missing_member_event_ids = []
-        for event_id in member_event_ids:
-            ev_entry = event_map.get(event_id)
-            if ev_entry:
-                if ev_entry.event.membership == Membership.JOIN:
-                    users_in_room[to_ascii(ev_entry.event.state_key)] = ProfileInfo(
-                        display_name=to_ascii(
-                            ev_entry.event.content.get("displayname", None)
-                        ),
-                        avatar_url=to_ascii(
-                            ev_entry.event.content.get("avatar_url", None)
-                        ),
-                    )
-            else:
-                missing_member_event_ids.append(event_id)
-
-        if missing_member_event_ids:
-            event_to_memberships = yield self._get_joined_profiles_from_event_ids(
-                missing_member_event_ids
-            )
-            users_in_room.update((row for row in event_to_memberships.values() if row))
-
-        if event is not None and event.type == EventTypes.Member:
-            if event.membership == Membership.JOIN:
-                if event.event_id in member_event_ids:
-                    users_in_room[to_ascii(event.state_key)] = ProfileInfo(
-                        display_name=to_ascii(event.content.get("displayname", None)),
-                        avatar_url=to_ascii(event.content.get("avatar_url", None)),
-                    )
-
-        return users_in_room
-
-    @cached(max_entries=10000)
-    def _get_joined_profile_from_event_id(self, event_id):
-        raise NotImplementedError()
-
-    @cachedList(
-        cached_method_name="_get_joined_profile_from_event_id",
-        list_name="event_ids",
-        inlineCallbacks=True,
-    )
-    def _get_joined_profiles_from_event_ids(self, event_ids):
-        """For given set of member event_ids check if they point to a join
-        event and if so return the associated user and profile info.
-
-        Args:
-            event_ids (Iterable[str]): The member event IDs to lookup
-
-        Returns:
-            Deferred[dict[str, Tuple[str, ProfileInfo]|None]]: Map from event ID
-            to `user_id` and ProfileInfo (or None if not join event).
-        """
-
-        rows = yield self._simple_select_many_batch(
-            table="room_memberships",
-            column="event_id",
-            iterable=event_ids,
-            retcols=("user_id", "display_name", "avatar_url", "event_id"),
-            keyvalues={"membership": Membership.JOIN},
-            batch_size=500,
-            desc="_get_membership_from_event_ids",
-        )
-
-        return {
-            row["event_id"]: (
-                row["user_id"],
-                ProfileInfo(
-                    avatar_url=row["avatar_url"], display_name=row["display_name"]
-                ),
-            )
-            for row in rows
-        }
-
-    @cachedInlineCallbacks(max_entries=10000)
-    def is_host_joined(self, room_id, host):
-        if "%" in host or "_" in host:
-            raise Exception("Invalid host name")
-
-        sql = """
-            SELECT state_key FROM current_state_events AS c
-            INNER JOIN room_memberships AS m USING (event_id)
-            WHERE m.membership = 'join'
-                AND type = 'm.room.member'
-                AND c.room_id = ?
-                AND state_key LIKE ?
-            LIMIT 1
-        """
-
-        # We do need to be careful to ensure that host doesn't have any wild cards
-        # in it, but we checked above for known ones and we'll check below that
-        # the returned user actually has the correct domain.
-        like_clause = "%:" + host
-
-        rows = yield self._execute("is_host_joined", None, sql, room_id, like_clause)
-
-        if not rows:
-            return False
-
-        user_id = rows[0][0]
-        if get_domain_from_id(user_id) != host:
-            # This can only happen if the host name has something funky in it
-            raise Exception("Invalid host name")
-
-        return True
-
-    @cachedInlineCallbacks()
-    def was_host_joined(self, room_id, host):
-        """Check whether the server is or ever was in the room.
-
-        Args:
-            room_id (str)
-            host (str)
-
-        Returns:
-            Deferred: Resolves to True if the host is/was in the room, otherwise
-            False.
-        """
-        if "%" in host or "_" in host:
-            raise Exception("Invalid host name")
-
-        sql = """
-            SELECT user_id FROM room_memberships
-            WHERE room_id = ?
-                AND user_id LIKE ?
-                AND membership = 'join'
-            LIMIT 1
-        """
-
-        # We do need to be careful to ensure that host doesn't have any wild cards
-        # in it, but we checked above for known ones and we'll check below that
-        # the returned user actually has the correct domain.
-        like_clause = "%:" + host
-
-        rows = yield self._execute("was_host_joined", None, sql, room_id, like_clause)
-
-        if not rows:
-            return False
-
-        user_id = rows[0][0]
-        if get_domain_from_id(user_id) != host:
-            # This can only happen if the host name has something funky in it
-            raise Exception("Invalid host name")
-
-        return True
-
-    @defer.inlineCallbacks
-    def get_joined_hosts(self, room_id, state_entry):
-        state_group = state_entry.state_group
-        if not state_group:
-            # If state_group is None it means it has yet to be assigned a
-            # state group, i.e. we need to make sure that calls with a state_group
-            # of None don't hit previous cached calls with a None state_group.
-            # To do this we set the state_group to a new object as object() != object()
-            state_group = object()
-
-        with Measure(self._clock, "get_joined_hosts"):
-            return (
-                yield self._get_joined_hosts(
-                    room_id, state_group, state_entry.state, state_entry=state_entry
-                )
-            )
-
-    @cachedInlineCallbacks(num_args=2, max_entries=10000, iterable=True)
-    # @defer.inlineCallbacks
-    def _get_joined_hosts(self, room_id, state_group, current_state_ids, state_entry):
-        # We don't use `state_group`, its there so that we can cache based
-        # on it. However, its important that its never None, since two current_state's
-        # with a state_group of None are likely to be different.
-        # See bulk_get_push_rules_for_room for how we work around this.
-        assert state_group is not None
-
-        cache = self._get_joined_hosts_cache(room_id)
-        joined_hosts = yield cache.get_destinations(state_entry)
-
-        return joined_hosts
-
-    @cached(max_entries=10000)
-    def _get_joined_hosts_cache(self, room_id):
-        return _JoinedHostsCache(self, room_id)
-
-    @cachedInlineCallbacks(num_args=2)
-    def did_forget(self, user_id, room_id):
-        """Returns whether user_id has elected to discard history for room_id.
-
-        Returns False if they have since re-joined."""
-
-        def f(txn):
-            sql = (
-                "SELECT"
-                "  COUNT(*)"
-                " FROM"
-                "  room_memberships"
-                " WHERE"
-                "  user_id = ?"
-                " AND"
-                "  room_id = ?"
-                " AND"
-                "  forgotten = 0"
-            )
-            txn.execute(sql, (user_id, room_id))
-            rows = txn.fetchall()
-            return rows[0][0]
-
-        count = yield self.runInteraction("did_forget_membership", f)
-        return count == 0
-
-    @cached()
-    def get_forgotten_rooms_for_user(self, user_id):
-        """Gets all rooms the user has forgotten.
-
-        Args:
-            user_id (str)
-
-        Returns:
-            Deferred[set[str]]
-        """
-
-        def _get_forgotten_rooms_for_user_txn(txn):
-            # This is a slightly convoluted query that first looks up all rooms
-            # that the user has forgotten in the past, then rechecks that list
-            # to see if any have subsequently been updated. This is done so that
-            # we can use a partial index on `forgotten = 1` on the assumption
-            # that few users will actually forget many rooms.
-            #
-            # Note that a room is considered "forgotten" if *all* membership
-            # events for that user and room have the forgotten field set (as
-            # when a user forgets a room we update all rows for that user and
-            # room, not just the current one).
-            sql = """
-                SELECT room_id, (
-                    SELECT count(*) FROM room_memberships
-                    WHERE room_id = m.room_id AND user_id = m.user_id AND forgotten = 0
-                ) AS count
-                FROM room_memberships AS m
-                WHERE user_id = ? AND forgotten = 1
-                GROUP BY room_id, user_id;
-            """
-            txn.execute(sql, (user_id,))
-            return set(row[0] for row in txn if row[1] == 0)
-
-        return self.runInteraction(
-            "get_forgotten_rooms_for_user", _get_forgotten_rooms_for_user_txn
-        )
-
-    @defer.inlineCallbacks
-    def get_rooms_user_has_been_in(self, user_id):
-        """Get all rooms that the user has ever been in.
-
-        Args:
-            user_id (str)
-
-        Returns:
-            Deferred[set[str]]: Set of room IDs.
-        """
-
-        room_ids = yield self._simple_select_onecol(
-            table="room_memberships",
-            keyvalues={"membership": Membership.JOIN, "user_id": user_id},
-            retcol="room_id",
-            desc="get_rooms_user_has_been_in",
-        )
-
-        return set(room_ids)
-
-
-class RoomMemberBackgroundUpdateStore(BackgroundUpdateStore):
-    def __init__(self, db_conn, hs):
-        super(RoomMemberBackgroundUpdateStore, self).__init__(db_conn, hs)
-        self.register_background_update_handler(
-            _MEMBERSHIP_PROFILE_UPDATE_NAME, self._background_add_membership_profile
-        )
-        self.register_background_update_handler(
-            _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME,
-            self._background_current_state_membership,
-        )
-        self.register_background_index_update(
-            "room_membership_forgotten_idx",
-            index_name="room_memberships_user_room_forgotten",
-            table="room_memberships",
-            columns=["user_id", "room_id"],
-            where_clause="forgotten = 1",
-        )
-
-    @defer.inlineCallbacks
-    def _background_add_membership_profile(self, progress, batch_size):
-        target_min_stream_id = progress.get(
-            "target_min_stream_id_inclusive", self._min_stream_order_on_start
-        )
-        max_stream_id = progress.get(
-            "max_stream_id_exclusive", self._stream_order_on_start + 1
-        )
-
-        INSERT_CLUMP_SIZE = 1000
-
-        def add_membership_profile_txn(txn):
-            sql = """
-                SELECT stream_ordering, event_id, events.room_id, event_json.json
-                FROM events
-                INNER JOIN event_json USING (event_id)
-                INNER JOIN room_memberships USING (event_id)
-                WHERE ? <= stream_ordering AND stream_ordering < ?
-                AND type = 'm.room.member'
-                ORDER BY stream_ordering DESC
-                LIMIT ?
-            """
-
-            txn.execute(sql, (target_min_stream_id, max_stream_id, batch_size))
-
-            rows = self.cursor_to_dict(txn)
-            if not rows:
-                return 0
-
-            min_stream_id = rows[-1]["stream_ordering"]
-
-            to_update = []
-            for row in rows:
-                event_id = row["event_id"]
-                room_id = row["room_id"]
-                try:
-                    event_json = json.loads(row["json"])
-                    content = event_json["content"]
-                except Exception:
-                    continue
-
-                display_name = content.get("displayname", None)
-                avatar_url = content.get("avatar_url", None)
-
-                if display_name or avatar_url:
-                    to_update.append((display_name, avatar_url, event_id, room_id))
-
-            to_update_sql = """
-                UPDATE room_memberships SET display_name = ?, avatar_url = ?
-                WHERE event_id = ? AND room_id = ?
-            """
-            for index in range(0, len(to_update), INSERT_CLUMP_SIZE):
-                clump = to_update[index : index + INSERT_CLUMP_SIZE]
-                txn.executemany(to_update_sql, clump)
-
-            progress = {
-                "target_min_stream_id_inclusive": target_min_stream_id,
-                "max_stream_id_exclusive": min_stream_id,
-            }
-
-            self._background_update_progress_txn(
-                txn, _MEMBERSHIP_PROFILE_UPDATE_NAME, progress
-            )
-
-            return len(rows)
-
-        result = yield self.runInteraction(
-            _MEMBERSHIP_PROFILE_UPDATE_NAME, add_membership_profile_txn
-        )
-
-        if not result:
-            yield self._end_background_update(_MEMBERSHIP_PROFILE_UPDATE_NAME)
-
-        return result
-
-    @defer.inlineCallbacks
-    def _background_current_state_membership(self, progress, batch_size):
-        """Update the new membership column on current_state_events.
-
-        This works by iterating over all rooms in alphebetical order.
-        """
-
-        def _background_current_state_membership_txn(txn, last_processed_room):
-            processed = 0
-            while processed < batch_size:
-                txn.execute(
-                    """
-                        SELECT MIN(room_id) FROM current_state_events WHERE room_id > ?
-                    """,
-                    (last_processed_room,),
-                )
-                row = txn.fetchone()
-                if not row or not row[0]:
-                    return processed, True
-
-                next_room, = row
-
-                sql = """
-                    UPDATE current_state_events
-                    SET membership = (
-                        SELECT membership FROM room_memberships
-                        WHERE event_id = current_state_events.event_id
-                    )
-                    WHERE room_id = ?
-                """
-                txn.execute(sql, (next_room,))
-                processed += txn.rowcount
-
-                last_processed_room = next_room
-
-            self._background_update_progress_txn(
-                txn,
-                _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME,
-                {"last_processed_room": last_processed_room},
-            )
-
-            return processed, False
-
-        # If we haven't got a last processed room then just use the empty
-        # string, which will compare before all room IDs correctly.
-        last_processed_room = progress.get("last_processed_room", "")
-
-        row_count, finished = yield self.runInteraction(
-            "_background_current_state_membership_update",
-            _background_current_state_membership_txn,
-            last_processed_room,
-        )
-
-        if finished:
-            yield self._end_background_update(_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME)
-
-        return row_count
-
-
-class RoomMemberStore(RoomMemberWorkerStore, RoomMemberBackgroundUpdateStore):
-    def __init__(self, db_conn, hs):
-        super(RoomMemberStore, self).__init__(db_conn, hs)
-
-    def _store_room_members_txn(self, txn, events, backfilled):
-        """Store a room member in the database.
-        """
-        self._simple_insert_many_txn(
-            txn,
-            table="room_memberships",
-            values=[
-                {
-                    "event_id": event.event_id,
-                    "user_id": event.state_key,
-                    "sender": event.user_id,
-                    "room_id": event.room_id,
-                    "membership": event.membership,
-                    "display_name": event.content.get("displayname", None),
-                    "avatar_url": event.content.get("avatar_url", None),
-                }
-                for event in events
-            ],
-        )
-
-        for event in events:
-            txn.call_after(
-                self._membership_stream_cache.entity_has_changed,
-                event.state_key,
-                event.internal_metadata.stream_ordering,
-            )
-            txn.call_after(
-                self.get_invited_rooms_for_user.invalidate, (event.state_key,)
-            )
-
-            # We update the local_invites table only if the event is "current",
-            # i.e., its something that has just happened. If the event is an
-            # outlier it is only current if its an "out of band membership",
-            # like a remote invite or a rejection of a remote invite.
-            is_new_state = not backfilled and (
-                not event.internal_metadata.is_outlier()
-                or event.internal_metadata.is_out_of_band_membership()
-            )
-            is_mine = self.hs.is_mine_id(event.state_key)
-            if is_new_state and is_mine:
-                if event.membership == Membership.INVITE:
-                    self._simple_insert_txn(
-                        txn,
-                        table="local_invites",
-                        values={
-                            "event_id": event.event_id,
-                            "invitee": event.state_key,
-                            "inviter": event.sender,
-                            "room_id": event.room_id,
-                            "stream_id": event.internal_metadata.stream_ordering,
-                        },
-                    )
-                else:
-                    sql = (
-                        "UPDATE local_invites SET stream_id = ?, replaced_by = ? WHERE"
-                        " room_id = ? AND invitee = ? AND locally_rejected is NULL"
-                        " AND replaced_by is NULL"
-                    )
-
-                    txn.execute(
-                        sql,
-                        (
-                            event.internal_metadata.stream_ordering,
-                            event.event_id,
-                            event.room_id,
-                            event.state_key,
-                        ),
-                    )
-
-    @defer.inlineCallbacks
-    def locally_reject_invite(self, user_id, room_id):
-        sql = (
-            "UPDATE local_invites SET stream_id = ?, locally_rejected = ? WHERE"
-            " room_id = ? AND invitee = ? AND locally_rejected is NULL"
-            " AND replaced_by is NULL"
-        )
-
-        def f(txn, stream_ordering):
-            txn.execute(sql, (stream_ordering, True, room_id, user_id))
-
-        with self._stream_id_gen.get_next() as stream_ordering:
-            yield self.runInteraction("locally_reject_invite", f, stream_ordering)
-
-    def forget(self, user_id, room_id):
-        """Indicate that user_id wishes to discard history for room_id."""
-
-        def f(txn):
-            sql = (
-                "UPDATE"
-                "  room_memberships"
-                " SET"
-                "  forgotten = 1"
-                " WHERE"
-                "  user_id = ?"
-                " AND"
-                "  room_id = ?"
-            )
-            txn.execute(sql, (user_id, room_id))
-
-            self._invalidate_cache_and_stream(txn, self.did_forget, (user_id, room_id))
-            self._invalidate_cache_and_stream(
-                txn, self.get_forgotten_rooms_for_user, (user_id,)
-            )
-
-        return self.runInteraction("forget_membership", f)
-
-
-class _JoinedHostsCache(object):
-    """Cache for joined hosts in a room that is optimised to handle updates
-    via state deltas.
-    """
-
-    def __init__(self, store, room_id):
-        self.store = store
-        self.room_id = room_id
-
-        self.hosts_to_joined_users = {}
-
-        self.state_group = object()
-
-        self.linearizer = Linearizer("_JoinedHostsCache")
-
-        self._len = 0
-
-    @defer.inlineCallbacks
-    def get_destinations(self, state_entry):
-        """Get set of destinations for a state entry
-
-        Args:
-            state_entry(synapse.state._StateCacheEntry)
-        """
-        if state_entry.state_group == self.state_group:
-            return frozenset(self.hosts_to_joined_users)
-
-        with (yield self.linearizer.queue(())):
-            if state_entry.state_group == self.state_group:
-                pass
-            elif state_entry.prev_group == self.state_group:
-                for (typ, state_key), event_id in iteritems(state_entry.delta_ids):
-                    if typ != EventTypes.Member:
-                        continue
-
-                    host = intern_string(get_domain_from_id(state_key))
-                    user_id = state_key
-                    known_joins = self.hosts_to_joined_users.setdefault(host, set())
-
-                    event = yield self.store.get_event(event_id)
-                    if event.membership == Membership.JOIN:
-                        known_joins.add(user_id)
-                    else:
-                        known_joins.discard(user_id)
-
-                        if not known_joins:
-                            self.hosts_to_joined_users.pop(host, None)
-            else:
-                joined_users = yield self.store.get_joined_users_from_state(
-                    self.room_id, state_entry
-                )
-
-                self.hosts_to_joined_users = {}
-                for user_id in joined_users:
-                    host = intern_string(get_domain_from_id(user_id))
-                    self.hosts_to_joined_users.setdefault(host, set()).add(user_id)
-
-            if state_entry.state_group:
-                self.state_group = state_entry.state_group
-            else:
-                self.state_group = object()
-            self._len = sum(len(v) for v in itervalues(self.hosts_to_joined_users))
-        return frozenset(self.hosts_to_joined_users)
-
-    def __len__(self):
-        return self._len
diff --git a/synapse/storage/schema/delta/35/00background_updates_add_col.sql b/synapse/storage/schema/delta/35/00background_updates_add_col.sql
new file mode 100644
index 0000000000..c2d2a4f836
--- /dev/null
+++ b/synapse/storage/schema/delta/35/00background_updates_add_col.sql
@@ -0,0 +1,17 @@
+/* Copyright 2016 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+ALTER TABLE background_updates ADD COLUMN depends_on TEXT;
diff --git a/synapse/storage/schema/full_schemas/54/full.sql b/synapse/storage/schema/full_schemas/54/full.sql
new file mode 100644
index 0000000000..1005880466
--- /dev/null
+++ b/synapse/storage/schema/full_schemas/54/full.sql
@@ -0,0 +1,8 @@
+
+
+CREATE TABLE background_updates (
+    update_name text NOT NULL,
+    progress_json text NOT NULL,
+    depends_on text,
+    CONSTRAINT background_updates_uniqueness UNIQUE (update_name)
+);
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index a941a5ae3f..a2df8fa827 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -14,45 +14,16 @@
 # limitations under the License.
 
 import logging
-from collections import namedtuple
 
 from six import iteritems, itervalues
-from six.moves import range
 
 import attr
 
-from twisted.internet import defer
-
 from synapse.api.constants import EventTypes
-from synapse.api.errors import NotFoundError
-from synapse.storage._base import SQLBaseStore
-from synapse.storage.background_updates import BackgroundUpdateStore
-from synapse.storage.engines import PostgresEngine
-from synapse.storage.events_worker import EventsWorkerStore
-from synapse.util.caches import get_cache_factor_for, intern_string
-from synapse.util.caches.descriptors import cached, cachedList
-from synapse.util.caches.dictionary_cache import DictionaryCache
-from synapse.util.stringutils import to_ascii
 
 logger = logging.getLogger(__name__)
 
 
-MAX_STATE_DELTA_HOPS = 100
-
-
-class _GetStateGroupDelta(
-    namedtuple("_GetStateGroupDelta", ("prev_group", "delta_ids"))
-):
-    """Return type of get_state_group_delta that implements __len__, which lets
-    us use the itrable flag when caching
-    """
-
-    __slots__ = []
-
-    def __len__(self):
-        return len(self.delta_ids) if self.delta_ids else 0
-
-
 @attr.s(slots=True)
 class StateFilter(object):
     """A filter used when querying for state.
@@ -351,1195 +322,3 @@ class StateFilter(object):
         )
 
         return member_filter, non_member_filter
-
-
-class StateGroupBackgroundUpdateStore(SQLBaseStore):
-    """Defines functions related to state groups needed to run the state backgroud
-    updates.
-    """
-
-    def _count_state_group_hops_txn(self, txn, state_group):
-        """Given a state group, count how many hops there are in the tree.
-
-        This is used to ensure the delta chains don't get too long.
-        """
-        if isinstance(self.database_engine, PostgresEngine):
-            sql = """
-                WITH RECURSIVE state(state_group) AS (
-                    VALUES(?::bigint)
-                    UNION ALL
-                    SELECT prev_state_group FROM state_group_edges e, state s
-                    WHERE s.state_group = e.state_group
-                )
-                SELECT count(*) FROM state;
-            """
-
-            txn.execute(sql, (state_group,))
-            row = txn.fetchone()
-            if row and row[0]:
-                return row[0]
-            else:
-                return 0
-        else:
-            # We don't use WITH RECURSIVE on sqlite3 as there are distributions
-            # that ship with an sqlite3 version that doesn't support it (e.g. wheezy)
-            next_group = state_group
-            count = 0
-
-            while next_group:
-                next_group = self._simple_select_one_onecol_txn(
-                    txn,
-                    table="state_group_edges",
-                    keyvalues={"state_group": next_group},
-                    retcol="prev_state_group",
-                    allow_none=True,
-                )
-                if next_group:
-                    count += 1
-
-            return count
-
-    def _get_state_groups_from_groups_txn(
-        self, txn, groups, state_filter=StateFilter.all()
-    ):
-        results = {group: {} for group in groups}
-
-        where_clause, where_args = state_filter.make_sql_filter_clause()
-
-        # Unless the filter clause is empty, we're going to append it after an
-        # existing where clause
-        if where_clause:
-            where_clause = " AND (%s)" % (where_clause,)
-
-        if isinstance(self.database_engine, PostgresEngine):
-            # Temporarily disable sequential scans in this transaction. This is
-            # a temporary hack until we can add the right indices in
-            txn.execute("SET LOCAL enable_seqscan=off")
-
-            # The below query walks the state_group tree so that the "state"
-            # table includes all state_groups in the tree. It then joins
-            # against `state_groups_state` to fetch the latest state.
-            # It assumes that previous state groups are always numerically
-            # lesser.
-            # The PARTITION is used to get the event_id in the greatest state
-            # group for the given type, state_key.
-            # This may return multiple rows per (type, state_key), but last_value
-            # should be the same.
-            sql = """
-                WITH RECURSIVE state(state_group) AS (
-                    VALUES(?::bigint)
-                    UNION ALL
-                    SELECT prev_state_group FROM state_group_edges e, state s
-                    WHERE s.state_group = e.state_group
-                )
-                SELECT DISTINCT type, state_key, last_value(event_id) OVER (
-                    PARTITION BY type, state_key ORDER BY state_group ASC
-                    ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
-                ) AS event_id FROM state_groups_state
-                WHERE state_group IN (
-                    SELECT state_group FROM state
-                )
-            """
-
-            for group in groups:
-                args = [group]
-                args.extend(where_args)
-
-                txn.execute(sql + where_clause, args)
-                for row in txn:
-                    typ, state_key, event_id = row
-                    key = (typ, state_key)
-                    results[group][key] = event_id
-        else:
-            max_entries_returned = state_filter.max_entries_returned()
-
-            # We don't use WITH RECURSIVE on sqlite3 as there are distributions
-            # that ship with an sqlite3 version that doesn't support it (e.g. wheezy)
-            for group in groups:
-                next_group = group
-
-                while next_group:
-                    # We did this before by getting the list of group ids, and
-                    # then passing that list to sqlite to get latest event for
-                    # each (type, state_key). However, that was terribly slow
-                    # without the right indices (which we can't add until
-                    # after we finish deduping state, which requires this func)
-                    args = [next_group]
-                    args.extend(where_args)
-
-                    txn.execute(
-                        "SELECT type, state_key, event_id FROM state_groups_state"
-                        " WHERE state_group = ? " + where_clause,
-                        args,
-                    )
-                    results[group].update(
-                        ((typ, state_key), event_id)
-                        for typ, state_key, event_id in txn
-                        if (typ, state_key) not in results[group]
-                    )
-
-                    # If the number of entries in the (type,state_key)->event_id dict
-                    # matches the number of (type,state_keys) types we were searching
-                    # for, then we must have found them all, so no need to go walk
-                    # further down the tree... UNLESS our types filter contained
-                    # wildcards (i.e. Nones) in which case we have to do an exhaustive
-                    # search
-                    if (
-                        max_entries_returned is not None
-                        and len(results[group]) == max_entries_returned
-                    ):
-                        break
-
-                    next_group = self._simple_select_one_onecol_txn(
-                        txn,
-                        table="state_group_edges",
-                        keyvalues={"state_group": next_group},
-                        retcol="prev_state_group",
-                        allow_none=True,
-                    )
-
-        return results
-
-
-# this inherits from EventsWorkerStore because it calls self.get_events
-class StateGroupWorkerStore(
-    EventsWorkerStore, StateGroupBackgroundUpdateStore, SQLBaseStore
-):
-    """The parts of StateGroupStore that can be called from workers.
-    """
-
-    STATE_GROUP_DEDUPLICATION_UPDATE_NAME = "state_group_state_deduplication"
-    STATE_GROUP_INDEX_UPDATE_NAME = "state_group_state_type_index"
-    CURRENT_STATE_INDEX_UPDATE_NAME = "current_state_members_idx"
-
-    def __init__(self, db_conn, hs):
-        super(StateGroupWorkerStore, self).__init__(db_conn, hs)
-
-        # Originally the state store used a single DictionaryCache to cache the
-        # event IDs for the state types in a given state group to avoid hammering
-        # on the state_group* tables.
-        #
-        # The point of using a DictionaryCache is that it can cache a subset
-        # of the state events for a given state group (i.e. a subset of the keys for a
-        # given dict which is an entry in the cache for a given state group ID).
-        #
-        # However, this poses problems when performing complicated queries
-        # on the store - for instance: "give me all the state for this group, but
-        # limit members to this subset of users", as DictionaryCache's API isn't
-        # rich enough to say "please cache any of these fields, apart from this subset".
-        # This is problematic when lazy loading members, which requires this behaviour,
-        # as without it the cache has no choice but to speculatively load all
-        # state events for the group, which negates the efficiency being sought.
-        #
-        # Rather than overcomplicating DictionaryCache's API, we instead split the
-        # state_group_cache into two halves - one for tracking non-member events,
-        # and the other for tracking member_events.  This means that lazy loading
-        # queries can be made in a cache-friendly manner by querying both caches
-        # separately and then merging the result.  So for the example above, you
-        # would query the members cache for a specific subset of state keys
-        # (which DictionaryCache will handle efficiently and fine) and the non-members
-        # cache for all state (which DictionaryCache will similarly handle fine)
-        # and then just merge the results together.
-        #
-        # We size the non-members cache to be smaller than the members cache as the
-        # vast majority of state in Matrix (today) is member events.
-
-        self._state_group_cache = DictionaryCache(
-            "*stateGroupCache*",
-            # TODO: this hasn't been tuned yet
-            50000 * get_cache_factor_for("stateGroupCache"),
-        )
-        self._state_group_members_cache = DictionaryCache(
-            "*stateGroupMembersCache*",
-            500000 * get_cache_factor_for("stateGroupMembersCache"),
-        )
-
-    @defer.inlineCallbacks
-    def get_room_version(self, room_id):
-        """Get the room_version of a given room
-
-        Args:
-            room_id (str)
-
-        Returns:
-            Deferred[str]
-
-        Raises:
-            NotFoundError if the room is unknown
-        """
-        # for now we do this by looking at the create event. We may want to cache this
-        # more intelligently in future.
-
-        # Retrieve the room's create event
-        create_event = yield self.get_create_event_for_room(room_id)
-        return create_event.content.get("room_version", "1")
-
-    @defer.inlineCallbacks
-    def get_room_predecessor(self, room_id):
-        """Get the predecessor room of an upgraded room if one exists.
-        Otherwise return None.
-
-        Args:
-            room_id (str)
-
-        Returns:
-            Deferred[unicode|None]: predecessor room id
-
-        Raises:
-            NotFoundError if the room is unknown
-        """
-        # Retrieve the room's create event
-        create_event = yield self.get_create_event_for_room(room_id)
-
-        # Return predecessor if present
-        return create_event.content.get("predecessor", None)
-
-    @defer.inlineCallbacks
-    def get_create_event_for_room(self, room_id):
-        """Get the create state event for a room.
-
-        Args:
-            room_id (str)
-
-        Returns:
-            Deferred[EventBase]: The room creation event.
-
-        Raises:
-            NotFoundError if the room is unknown
-        """
-        state_ids = yield self.get_current_state_ids(room_id)
-        create_id = state_ids.get((EventTypes.Create, ""))
-
-        # If we can't find the create event, assume we've hit a dead end
-        if not create_id:
-            raise NotFoundError("Unknown room %s" % (room_id))
-
-        # Retrieve the room's create event and return
-        create_event = yield self.get_event(create_id)
-        return create_event
-
-    @cached(max_entries=100000, iterable=True)
-    def get_current_state_ids(self, room_id):
-        """Get the current state event ids for a room based on the
-        current_state_events table.
-
-        Args:
-            room_id (str)
-
-        Returns:
-            deferred: dict of (type, state_key) -> event_id
-        """
-
-        def _get_current_state_ids_txn(txn):
-            txn.execute(
-                """SELECT type, state_key, event_id FROM current_state_events
-                WHERE room_id = ?
-                """,
-                (room_id,),
-            )
-
-            return {
-                (intern_string(r[0]), intern_string(r[1])): to_ascii(r[2]) for r in txn
-            }
-
-        return self.runInteraction("get_current_state_ids", _get_current_state_ids_txn)
-
-    # FIXME: how should this be cached?
-    def get_filtered_current_state_ids(self, room_id, state_filter=StateFilter.all()):
-        """Get the current state event of a given type for a room based on the
-        current_state_events table.  This may not be as up-to-date as the result
-        of doing a fresh state resolution as per state_handler.get_current_state
-
-        Args:
-            room_id (str)
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-
-        Returns:
-            Deferred[dict[tuple[str, str], str]]: Map from type/state_key to
-            event ID.
-        """
-
-        where_clause, where_args = state_filter.make_sql_filter_clause()
-
-        if not where_clause:
-            # We delegate to the cached version
-            return self.get_current_state_ids(room_id)
-
-        def _get_filtered_current_state_ids_txn(txn):
-            results = {}
-            sql = """
-                SELECT type, state_key, event_id FROM current_state_events
-                WHERE room_id = ?
-            """
-
-            if where_clause:
-                sql += " AND (%s)" % (where_clause,)
-
-            args = [room_id]
-            args.extend(where_args)
-            txn.execute(sql, args)
-            for row in txn:
-                typ, state_key, event_id = row
-                key = (intern_string(typ), intern_string(state_key))
-                results[key] = event_id
-
-            return results
-
-        return self.runInteraction(
-            "get_filtered_current_state_ids", _get_filtered_current_state_ids_txn
-        )
-
-    @defer.inlineCallbacks
-    def get_canonical_alias_for_room(self, room_id):
-        """Get canonical alias for room, if any
-
-        Args:
-            room_id (str)
-
-        Returns:
-            Deferred[str|None]: The canonical alias, if any
-        """
-
-        state = yield self.get_filtered_current_state_ids(
-            room_id, StateFilter.from_types([(EventTypes.CanonicalAlias, "")])
-        )
-
-        event_id = state.get((EventTypes.CanonicalAlias, ""))
-        if not event_id:
-            return
-
-        event = yield self.get_event(event_id, allow_none=True)
-        if not event:
-            return
-
-        return event.content.get("canonical_alias")
-
-    @cached(max_entries=10000, iterable=True)
-    def get_state_group_delta(self, state_group):
-        """Given a state group try to return a previous group and a delta between
-        the old and the new.
-
-        Returns:
-            (prev_group, delta_ids), where both may be None.
-        """
-
-        def _get_state_group_delta_txn(txn):
-            prev_group = self._simple_select_one_onecol_txn(
-                txn,
-                table="state_group_edges",
-                keyvalues={"state_group": state_group},
-                retcol="prev_state_group",
-                allow_none=True,
-            )
-
-            if not prev_group:
-                return _GetStateGroupDelta(None, None)
-
-            delta_ids = self._simple_select_list_txn(
-                txn,
-                table="state_groups_state",
-                keyvalues={"state_group": state_group},
-                retcols=("type", "state_key", "event_id"),
-            )
-
-            return _GetStateGroupDelta(
-                prev_group,
-                {(row["type"], row["state_key"]): row["event_id"] for row in delta_ids},
-            )
-
-        return self.runInteraction("get_state_group_delta", _get_state_group_delta_txn)
-
-    @defer.inlineCallbacks
-    def get_state_groups_ids(self, _room_id, event_ids):
-        """Get the event IDs of all the state for the state groups for the given events
-
-        Args:
-            _room_id (str): id of the room for these events
-            event_ids (iterable[str]): ids of the events
-
-        Returns:
-            Deferred[dict[int, dict[tuple[str, str], str]]]:
-                dict of state_group_id -> (dict of (type, state_key) -> event id)
-        """
-        if not event_ids:
-            return {}
-
-        event_to_groups = yield self._get_state_group_for_events(event_ids)
-
-        groups = set(itervalues(event_to_groups))
-        group_to_state = yield self._get_state_for_groups(groups)
-
-        return group_to_state
-
-    @defer.inlineCallbacks
-    def get_state_ids_for_group(self, state_group):
-        """Get the event IDs of all the state in the given state group
-
-        Args:
-            state_group (int)
-
-        Returns:
-            Deferred[dict]: Resolves to a map of (type, state_key) -> event_id
-        """
-        group_to_state = yield self._get_state_for_groups((state_group,))
-
-        return group_to_state[state_group]
-
-    @defer.inlineCallbacks
-    def get_state_groups(self, room_id, event_ids):
-        """ Get the state groups for the given list of event_ids
-
-        Returns:
-            Deferred[dict[int, list[EventBase]]]:
-                dict of state_group_id -> list of state events.
-        """
-        if not event_ids:
-            return {}
-
-        group_to_ids = yield self.get_state_groups_ids(room_id, event_ids)
-
-        state_event_map = yield self.get_events(
-            [
-                ev_id
-                for group_ids in itervalues(group_to_ids)
-                for ev_id in itervalues(group_ids)
-            ],
-            get_prev_content=False,
-        )
-
-        return {
-            group: [
-                state_event_map[v]
-                for v in itervalues(event_id_map)
-                if v in state_event_map
-            ]
-            for group, event_id_map in iteritems(group_to_ids)
-        }
-
-    @defer.inlineCallbacks
-    def _get_state_groups_from_groups(self, groups, state_filter):
-        """Returns the state groups for a given set of groups, filtering on
-        types of state events.
-
-        Args:
-            groups(list[int]): list of state group IDs to query
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-        Returns:
-            Deferred[dict[int, dict[tuple[str, str], str]]]:
-                dict of state_group_id -> (dict of (type, state_key) -> event id)
-        """
-        results = {}
-
-        chunks = [groups[i : i + 100] for i in range(0, len(groups), 100)]
-        for chunk in chunks:
-            res = yield self.runInteraction(
-                "_get_state_groups_from_groups",
-                self._get_state_groups_from_groups_txn,
-                chunk,
-                state_filter,
-            )
-            results.update(res)
-
-        return results
-
-    @defer.inlineCallbacks
-    def get_state_for_events(self, event_ids, state_filter=StateFilter.all()):
-        """Given a list of event_ids and type tuples, return a list of state
-        dicts for each event.
-
-        Args:
-            event_ids (list[string])
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-
-        Returns:
-            deferred: A dict of (event_id) -> (type, state_key) -> [state_events]
-        """
-        event_to_groups = yield self._get_state_group_for_events(event_ids)
-
-        groups = set(itervalues(event_to_groups))
-        group_to_state = yield self._get_state_for_groups(groups, state_filter)
-
-        state_event_map = yield self.get_events(
-            [ev_id for sd in itervalues(group_to_state) for ev_id in itervalues(sd)],
-            get_prev_content=False,
-        )
-
-        event_to_state = {
-            event_id: {
-                k: state_event_map[v]
-                for k, v in iteritems(group_to_state[group])
-                if v in state_event_map
-            }
-            for event_id, group in iteritems(event_to_groups)
-        }
-
-        return {event: event_to_state[event] for event in event_ids}
-
-    @defer.inlineCallbacks
-    def get_state_ids_for_events(self, event_ids, state_filter=StateFilter.all()):
-        """
-        Get the state dicts corresponding to a list of events, containing the event_ids
-        of the state events (as opposed to the events themselves)
-
-        Args:
-            event_ids(list(str)): events whose state should be returned
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-
-        Returns:
-            A deferred dict from event_id -> (type, state_key) -> event_id
-        """
-        event_to_groups = yield self._get_state_group_for_events(event_ids)
-
-        groups = set(itervalues(event_to_groups))
-        group_to_state = yield self._get_state_for_groups(groups, state_filter)
-
-        event_to_state = {
-            event_id: group_to_state[group]
-            for event_id, group in iteritems(event_to_groups)
-        }
-
-        return {event: event_to_state[event] for event in event_ids}
-
-    @defer.inlineCallbacks
-    def get_state_for_event(self, event_id, state_filter=StateFilter.all()):
-        """
-        Get the state dict corresponding to a particular event
-
-        Args:
-            event_id(str): event whose state should be returned
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-
-        Returns:
-            A deferred dict from (type, state_key) -> state_event
-        """
-        state_map = yield self.get_state_for_events([event_id], state_filter)
-        return state_map[event_id]
-
-    @defer.inlineCallbacks
-    def get_state_ids_for_event(self, event_id, state_filter=StateFilter.all()):
-        """
-        Get the state dict corresponding to a particular event
-
-        Args:
-            event_id(str): event whose state should be returned
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-
-        Returns:
-            A deferred dict from (type, state_key) -> state_event
-        """
-        state_map = yield self.get_state_ids_for_events([event_id], state_filter)
-        return state_map[event_id]
-
-    @cached(max_entries=50000)
-    def _get_state_group_for_event(self, event_id):
-        return self._simple_select_one_onecol(
-            table="event_to_state_groups",
-            keyvalues={"event_id": event_id},
-            retcol="state_group",
-            allow_none=True,
-            desc="_get_state_group_for_event",
-        )
-
-    @cachedList(
-        cached_method_name="_get_state_group_for_event",
-        list_name="event_ids",
-        num_args=1,
-        inlineCallbacks=True,
-    )
-    def _get_state_group_for_events(self, event_ids):
-        """Returns mapping event_id -> state_group
-        """
-        rows = yield self._simple_select_many_batch(
-            table="event_to_state_groups",
-            column="event_id",
-            iterable=event_ids,
-            keyvalues={},
-            retcols=("event_id", "state_group"),
-            desc="_get_state_group_for_events",
-        )
-
-        return {row["event_id"]: row["state_group"] for row in rows}
-
-    def _get_state_for_group_using_cache(self, cache, group, state_filter):
-        """Checks if group is in cache. See `_get_state_for_groups`
-
-        Args:
-            cache(DictionaryCache): the state group cache to use
-            group(int): The state group to lookup
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-
-        Returns 2-tuple (`state_dict`, `got_all`).
-        `got_all` is a bool indicating if we successfully retrieved all
-        requests state from the cache, if False we need to query the DB for the
-        missing state.
-        """
-        is_all, known_absent, state_dict_ids = cache.get(group)
-
-        if is_all or state_filter.is_full():
-            # Either we have everything or want everything, either way
-            # `is_all` tells us whether we've gotten everything.
-            return state_filter.filter_state(state_dict_ids), is_all
-
-        # tracks whether any of our requested types are missing from the cache
-        missing_types = False
-
-        if state_filter.has_wildcards():
-            # We don't know if we fetched all the state keys for the types in
-            # the filter that are wildcards, so we have to assume that we may
-            # have missed some.
-            missing_types = True
-        else:
-            # There aren't any wild cards, so `concrete_types()` returns the
-            # complete list of event types we're wanting.
-            for key in state_filter.concrete_types():
-                if key not in state_dict_ids and key not in known_absent:
-                    missing_types = True
-                    break
-
-        return state_filter.filter_state(state_dict_ids), not missing_types
-
-    @defer.inlineCallbacks
-    def _get_state_for_groups(self, groups, state_filter=StateFilter.all()):
-        """Gets the state at each of a list of state groups, optionally
-        filtering by type/state_key
-
-        Args:
-            groups (iterable[int]): list of state groups for which we want
-                to get the state.
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-        Returns:
-            Deferred[dict[int, dict[tuple[str, str], str]]]:
-                dict of state_group_id -> (dict of (type, state_key) -> event id)
-        """
-
-        member_filter, non_member_filter = state_filter.get_member_split()
-
-        # Now we look them up in the member and non-member caches
-        non_member_state, incomplete_groups_nm, = (
-            yield self._get_state_for_groups_using_cache(
-                groups, self._state_group_cache, state_filter=non_member_filter
-            )
-        )
-
-        member_state, incomplete_groups_m, = (
-            yield self._get_state_for_groups_using_cache(
-                groups, self._state_group_members_cache, state_filter=member_filter
-            )
-        )
-
-        state = dict(non_member_state)
-        for group in groups:
-            state[group].update(member_state[group])
-
-        # Now fetch any missing groups from the database
-
-        incomplete_groups = incomplete_groups_m | incomplete_groups_nm
-
-        if not incomplete_groups:
-            return state
-
-        cache_sequence_nm = self._state_group_cache.sequence
-        cache_sequence_m = self._state_group_members_cache.sequence
-
-        # Help the cache hit ratio by expanding the filter a bit
-        db_state_filter = state_filter.return_expanded()
-
-        group_to_state_dict = yield self._get_state_groups_from_groups(
-            list(incomplete_groups), state_filter=db_state_filter
-        )
-
-        # Now lets update the caches
-        self._insert_into_cache(
-            group_to_state_dict,
-            db_state_filter,
-            cache_seq_num_members=cache_sequence_m,
-            cache_seq_num_non_members=cache_sequence_nm,
-        )
-
-        # And finally update the result dict, by filtering out any extra
-        # stuff we pulled out of the database.
-        for group, group_state_dict in iteritems(group_to_state_dict):
-            # We just replace any existing entries, as we will have loaded
-            # everything we need from the database anyway.
-            state[group] = state_filter.filter_state(group_state_dict)
-
-        return state
-
-    def _get_state_for_groups_using_cache(self, groups, cache, state_filter):
-        """Gets the state at each of a list of state groups, optionally
-        filtering by type/state_key, querying from a specific cache.
-
-        Args:
-            groups (iterable[int]): list of state groups for which we want
-                to get the state.
-            cache (DictionaryCache): the cache of group ids to state dicts which
-                we will pass through - either the normal state cache or the specific
-                members state cache.
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-
-        Returns:
-            tuple[dict[int, dict[tuple[str, str], str]], set[int]]: Tuple of
-            dict of state_group_id -> (dict of (type, state_key) -> event id)
-            of entries in the cache, and the state group ids either missing
-            from the cache or incomplete.
-        """
-        results = {}
-        incomplete_groups = set()
-        for group in set(groups):
-            state_dict_ids, got_all = self._get_state_for_group_using_cache(
-                cache, group, state_filter
-            )
-            results[group] = state_dict_ids
-
-            if not got_all:
-                incomplete_groups.add(group)
-
-        return results, incomplete_groups
-
-    def _insert_into_cache(
-        self,
-        group_to_state_dict,
-        state_filter,
-        cache_seq_num_members,
-        cache_seq_num_non_members,
-    ):
-        """Inserts results from querying the database into the relevant cache.
-
-        Args:
-            group_to_state_dict (dict): The new entries pulled from database.
-                Map from state group to state dict
-            state_filter (StateFilter): The state filter used to fetch state
-                from the database.
-            cache_seq_num_members (int): Sequence number of member cache since
-                last lookup in cache
-            cache_seq_num_non_members (int): Sequence number of member cache since
-                last lookup in cache
-        """
-
-        # We need to work out which types we've fetched from the DB for the
-        # member vs non-member caches. This should be as accurate as possible,
-        # but can be an underestimate (e.g. when we have wild cards)
-
-        member_filter, non_member_filter = state_filter.get_member_split()
-        if member_filter.is_full():
-            # We fetched all member events
-            member_types = None
-        else:
-            # `concrete_types()` will only return a subset when there are wild
-            # cards in the filter, but that's fine.
-            member_types = member_filter.concrete_types()
-
-        if non_member_filter.is_full():
-            # We fetched all non member events
-            non_member_types = None
-        else:
-            non_member_types = non_member_filter.concrete_types()
-
-        for group, group_state_dict in iteritems(group_to_state_dict):
-            state_dict_members = {}
-            state_dict_non_members = {}
-
-            for k, v in iteritems(group_state_dict):
-                if k[0] == EventTypes.Member:
-                    state_dict_members[k] = v
-                else:
-                    state_dict_non_members[k] = v
-
-            self._state_group_members_cache.update(
-                cache_seq_num_members,
-                key=group,
-                value=state_dict_members,
-                fetched_keys=member_types,
-            )
-
-            self._state_group_cache.update(
-                cache_seq_num_non_members,
-                key=group,
-                value=state_dict_non_members,
-                fetched_keys=non_member_types,
-            )
-
-    def store_state_group(
-        self, event_id, room_id, prev_group, delta_ids, current_state_ids
-    ):
-        """Store a new set of state, returning a newly assigned state group.
-
-        Args:
-            event_id (str): The event ID for which the state was calculated
-            room_id (str)
-            prev_group (int|None): A previous state group for the room, optional.
-            delta_ids (dict|None): The delta between state at `prev_group` and
-                `current_state_ids`, if `prev_group` was given. Same format as
-                `current_state_ids`.
-            current_state_ids (dict): The state to store. Map of (type, state_key)
-                to event_id.
-
-        Returns:
-            Deferred[int]: The state group ID
-        """
-
-        def _store_state_group_txn(txn):
-            if current_state_ids is None:
-                # AFAIK, this can never happen
-                raise Exception("current_state_ids cannot be None")
-
-            state_group = self.database_engine.get_next_state_group_id(txn)
-
-            self._simple_insert_txn(
-                txn,
-                table="state_groups",
-                values={"id": state_group, "room_id": room_id, "event_id": event_id},
-            )
-
-            # We persist as a delta if we can, while also ensuring the chain
-            # of deltas isn't tooo long, as otherwise read performance degrades.
-            if prev_group:
-                is_in_db = self._simple_select_one_onecol_txn(
-                    txn,
-                    table="state_groups",
-                    keyvalues={"id": prev_group},
-                    retcol="id",
-                    allow_none=True,
-                )
-                if not is_in_db:
-                    raise Exception(
-                        "Trying to persist state with unpersisted prev_group: %r"
-                        % (prev_group,)
-                    )
-
-                potential_hops = self._count_state_group_hops_txn(txn, prev_group)
-            if prev_group and potential_hops < MAX_STATE_DELTA_HOPS:
-                self._simple_insert_txn(
-                    txn,
-                    table="state_group_edges",
-                    values={"state_group": state_group, "prev_state_group": prev_group},
-                )
-
-                self._simple_insert_many_txn(
-                    txn,
-                    table="state_groups_state",
-                    values=[
-                        {
-                            "state_group": state_group,
-                            "room_id": room_id,
-                            "type": key[0],
-                            "state_key": key[1],
-                            "event_id": state_id,
-                        }
-                        for key, state_id in iteritems(delta_ids)
-                    ],
-                )
-            else:
-                self._simple_insert_many_txn(
-                    txn,
-                    table="state_groups_state",
-                    values=[
-                        {
-                            "state_group": state_group,
-                            "room_id": room_id,
-                            "type": key[0],
-                            "state_key": key[1],
-                            "event_id": state_id,
-                        }
-                        for key, state_id in iteritems(current_state_ids)
-                    ],
-                )
-
-            # Prefill the state group caches with this group.
-            # It's fine to use the sequence like this as the state group map
-            # is immutable. (If the map wasn't immutable then this prefill could
-            # race with another update)
-
-            current_member_state_ids = {
-                s: ev
-                for (s, ev) in iteritems(current_state_ids)
-                if s[0] == EventTypes.Member
-            }
-            txn.call_after(
-                self._state_group_members_cache.update,
-                self._state_group_members_cache.sequence,
-                key=state_group,
-                value=dict(current_member_state_ids),
-            )
-
-            current_non_member_state_ids = {
-                s: ev
-                for (s, ev) in iteritems(current_state_ids)
-                if s[0] != EventTypes.Member
-            }
-            txn.call_after(
-                self._state_group_cache.update,
-                self._state_group_cache.sequence,
-                key=state_group,
-                value=dict(current_non_member_state_ids),
-            )
-
-            return state_group
-
-        return self.runInteraction("store_state_group", _store_state_group_txn)
-
-
-class StateBackgroundUpdateStore(
-    StateGroupBackgroundUpdateStore, BackgroundUpdateStore
-):
-
-    STATE_GROUP_DEDUPLICATION_UPDATE_NAME = "state_group_state_deduplication"
-    STATE_GROUP_INDEX_UPDATE_NAME = "state_group_state_type_index"
-    CURRENT_STATE_INDEX_UPDATE_NAME = "current_state_members_idx"
-    EVENT_STATE_GROUP_INDEX_UPDATE_NAME = "event_to_state_groups_sg_index"
-
-    def __init__(self, db_conn, hs):
-        super(StateBackgroundUpdateStore, self).__init__(db_conn, hs)
-        self.register_background_update_handler(
-            self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME,
-            self._background_deduplicate_state,
-        )
-        self.register_background_update_handler(
-            self.STATE_GROUP_INDEX_UPDATE_NAME, self._background_index_state
-        )
-        self.register_background_index_update(
-            self.CURRENT_STATE_INDEX_UPDATE_NAME,
-            index_name="current_state_events_member_index",
-            table="current_state_events",
-            columns=["state_key"],
-            where_clause="type='m.room.member'",
-        )
-        self.register_background_index_update(
-            self.EVENT_STATE_GROUP_INDEX_UPDATE_NAME,
-            index_name="event_to_state_groups_sg_index",
-            table="event_to_state_groups",
-            columns=["state_group"],
-        )
-
-    @defer.inlineCallbacks
-    def _background_deduplicate_state(self, progress, batch_size):
-        """This background update will slowly deduplicate state by reencoding
-        them as deltas.
-        """
-        last_state_group = progress.get("last_state_group", 0)
-        rows_inserted = progress.get("rows_inserted", 0)
-        max_group = progress.get("max_group", None)
-
-        BATCH_SIZE_SCALE_FACTOR = 100
-
-        batch_size = max(1, int(batch_size / BATCH_SIZE_SCALE_FACTOR))
-
-        if max_group is None:
-            rows = yield self._execute(
-                "_background_deduplicate_state",
-                None,
-                "SELECT coalesce(max(id), 0) FROM state_groups",
-            )
-            max_group = rows[0][0]
-
-        def reindex_txn(txn):
-            new_last_state_group = last_state_group
-            for count in range(batch_size):
-                txn.execute(
-                    "SELECT id, room_id FROM state_groups"
-                    " WHERE ? < id AND id <= ?"
-                    " ORDER BY id ASC"
-                    " LIMIT 1",
-                    (new_last_state_group, max_group),
-                )
-                row = txn.fetchone()
-                if row:
-                    state_group, room_id = row
-
-                if not row or not state_group:
-                    return True, count
-
-                txn.execute(
-                    "SELECT state_group FROM state_group_edges"
-                    " WHERE state_group = ?",
-                    (state_group,),
-                )
-
-                # If we reach a point where we've already started inserting
-                # edges we should stop.
-                if txn.fetchall():
-                    return True, count
-
-                txn.execute(
-                    "SELECT coalesce(max(id), 0) FROM state_groups"
-                    " WHERE id < ? AND room_id = ?",
-                    (state_group, room_id),
-                )
-                prev_group, = txn.fetchone()
-                new_last_state_group = state_group
-
-                if prev_group:
-                    potential_hops = self._count_state_group_hops_txn(txn, prev_group)
-                    if potential_hops >= MAX_STATE_DELTA_HOPS:
-                        # We want to ensure chains are at most this long,#
-                        # otherwise read performance degrades.
-                        continue
-
-                    prev_state = self._get_state_groups_from_groups_txn(
-                        txn, [prev_group]
-                    )
-                    prev_state = prev_state[prev_group]
-
-                    curr_state = self._get_state_groups_from_groups_txn(
-                        txn, [state_group]
-                    )
-                    curr_state = curr_state[state_group]
-
-                    if not set(prev_state.keys()) - set(curr_state.keys()):
-                        # We can only do a delta if the current has a strict super set
-                        # of keys
-
-                        delta_state = {
-                            key: value
-                            for key, value in iteritems(curr_state)
-                            if prev_state.get(key, None) != value
-                        }
-
-                        self._simple_delete_txn(
-                            txn,
-                            table="state_group_edges",
-                            keyvalues={"state_group": state_group},
-                        )
-
-                        self._simple_insert_txn(
-                            txn,
-                            table="state_group_edges",
-                            values={
-                                "state_group": state_group,
-                                "prev_state_group": prev_group,
-                            },
-                        )
-
-                        self._simple_delete_txn(
-                            txn,
-                            table="state_groups_state",
-                            keyvalues={"state_group": state_group},
-                        )
-
-                        self._simple_insert_many_txn(
-                            txn,
-                            table="state_groups_state",
-                            values=[
-                                {
-                                    "state_group": state_group,
-                                    "room_id": room_id,
-                                    "type": key[0],
-                                    "state_key": key[1],
-                                    "event_id": state_id,
-                                }
-                                for key, state_id in iteritems(delta_state)
-                            ],
-                        )
-
-            progress = {
-                "last_state_group": state_group,
-                "rows_inserted": rows_inserted + batch_size,
-                "max_group": max_group,
-            }
-
-            self._background_update_progress_txn(
-                txn, self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME, progress
-            )
-
-            return False, batch_size
-
-        finished, result = yield self.runInteraction(
-            self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME, reindex_txn
-        )
-
-        if finished:
-            yield self._end_background_update(
-                self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME
-            )
-
-        return result * BATCH_SIZE_SCALE_FACTOR
-
-    @defer.inlineCallbacks
-    def _background_index_state(self, progress, batch_size):
-        def reindex_txn(conn):
-            conn.rollback()
-            if isinstance(self.database_engine, PostgresEngine):
-                # postgres insists on autocommit for the index
-                conn.set_session(autocommit=True)
-                try:
-                    txn = conn.cursor()
-                    txn.execute(
-                        "CREATE INDEX CONCURRENTLY state_groups_state_type_idx"
-                        " ON state_groups_state(state_group, type, state_key)"
-                    )
-                    txn.execute("DROP INDEX IF EXISTS state_groups_state_id")
-                finally:
-                    conn.set_session(autocommit=False)
-            else:
-                txn = conn.cursor()
-                txn.execute(
-                    "CREATE INDEX state_groups_state_type_idx"
-                    " ON state_groups_state(state_group, type, state_key)"
-                )
-                txn.execute("DROP INDEX IF EXISTS state_groups_state_id")
-
-        yield self.runWithConnection(reindex_txn)
-
-        yield self._end_background_update(self.STATE_GROUP_INDEX_UPDATE_NAME)
-
-        return 1
-
-
-class StateStore(StateGroupWorkerStore, StateBackgroundUpdateStore):
-    """ Keeps track of the state at a given event.
-
-    This is done by the concept of `state groups`. Every event is a assigned
-    a state group (identified by an arbitrary string), which references a
-    collection of state events. The current state of an event is then the
-    collection of state events referenced by the event's state group.
-
-    Hence, every change in the current state causes a new state group to be
-    generated. However, if no change happens (e.g., if we get a message event
-    with only one parent it inherits the state group from its parent.)
-
-    There are three tables:
-      * `state_groups`: Stores group name, first event with in the group and
-        room id.
-      * `event_to_state_groups`: Maps events to state groups.
-      * `state_groups_state`: Maps state group to state events.
-    """
-
-    def __init__(self, db_conn, hs):
-        super(StateStore, self).__init__(db_conn, hs)
-
-    def _store_event_state_mappings_txn(self, txn, events_and_contexts):
-        state_groups = {}
-        for event, context in events_and_contexts:
-            if event.internal_metadata.is_outlier():
-                continue
-
-            # if the event was rejected, just give it the same state as its
-            # predecessor.
-            if context.rejected:
-                state_groups[event.event_id] = context.prev_group
-                continue
-
-            state_groups[event.event_id] = context.state_group
-
-        self._simple_insert_many_txn(
-            txn,
-            table="event_to_state_groups",
-            values=[
-                {"state_group": state_group_id, "event_id": event_id}
-                for event_id, state_group_id in iteritems(state_groups)
-            ],
-        )
-
-        for event_id, state_group_id in iteritems(state_groups):
-            txn.call_after(
-                self._get_state_group_for_event.prefill, (event_id,), state_group_id
-            )