Merge pull request #4837 from matrix-org/erikj/optional_prev_state

Make `prev_state` field optional

2 files changed, 2 insertions, 15 deletions

diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 990a5eaaae..428300ea0a 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -1407,21 +1407,6 @@ class EventsStore(StateGroupWorkerStore, EventFederationStore, EventsWorkerStore
             values=state_values,
         )
 
-        self._simple_insert_many_txn(
-            txn,
-            table="event_edges",
-            values=[
-                {
-                    "event_id": event.event_id,
-                    "prev_event_id": prev_id,
-                    "room_id": event.room_id,
-                    "is_state": True,
-                }
-                for event, _ in state_events_and_contexts
-                for prev_id, _ in event.prev_state
-            ],
-        )
-
         # Prefill the event cache
         self._add_to_cache(txn, events_and_contexts)
 
diff --git a/synapse/storage/schema/full_schemas/11/event_edges.sql b/synapse/storage/schema/full_schemas/11/event_edges.sql
index 52eec88357..bccd1c6f74 100644
--- a/synapse/storage/schema/full_schemas/11/event_edges.sql
+++ b/synapse/storage/schema/full_schemas/11/event_edges.sql
@@ -37,6 +37,8 @@ CREATE TABLE IF NOT EXISTS event_edges(
     event_id TEXT NOT NULL,
     prev_event_id TEXT NOT NULL,
     room_id TEXT NOT NULL,
+    -- We no longer insert prev_state into this table, so all new rows will have
+    -- is_state as false.
     is_state BOOL NOT NULL,
     UNIQUE (event_id, prev_event_id, room_id, is_state)
 );