Add a DB index to figure out past state at a stream ordering in a room

1 files changed, 37 insertions, 0 deletions

diff --git a/synapse/storage/schema/delta/35/stream_order_to_extrem.sql b/synapse/storage/schema/delta/35/stream_order_to_extrem.sql
new file mode 100644

index 0000000000..2b945d8a57
--- /dev/null
+++ b/synapse/storage/schema/delta/35/stream_order_to_extrem.sql
@@ -0,0 +1,37 @@
+/* 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.
+ */
+
+
+CREATE TABLE stream_ordering_to_exterm (
+    stream_ordering BIGINT NOT NULL,
+    room_id TEXT NOT NULL,
+    event_id TEXT NOT NULL
+);
+
+INSERT INTO stream_ordering_to_exterm (stream_ordering, room_id, event_id)
+    SELECT stream_ordering, room_id, event_id FROM event_forward_extremities
+    INNER JOIN (
+        SELECT room_id, max(stream_ordering) as stream_ordering FROM events
+        INNER JOIN event_forward_extremities USING (room_id, event_id)
+        GROUP BY room_id
+    ) AS rms USING (room_id);
+
+CREATE INDEX stream_ordering_to_exterm_idx on stream_ordering_to_exterm(
+    stream_ordering
+);
+
+CREATE INDEX stream_ordering_to_exterm_rm_idx on stream_ordering_to_exterm(
+    room_id, stream_ordering
+);