Add an index to make membership queries faster

synapse/storage/roommember.py

@@ -220,7 +220,7 @@ class RoomMemberStore(SQLBaseStore):
                 " ON e.event_id = c.event_id"
                 " AND m.room_id = c.room_id"
                 " AND m.user_id = c.state_key"
-                " WHERE %s"
+                " WHERE c.type = 'm.room.member' AND %s"
             ) % (where_clause,)
 
             txn.execute(sql, args)

synapse/storage/schema/delta/40/current_state_idx.sql

@@ -0,0 +1,17 @@
+/* Copyright 2017 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.
+ */
+
+INSERT INTO background_updates (update_name, progress_json) VALUES
+  ('current_state_members_idx', '{}');

synapse/storage/state.py

@@ -49,6 +49,7 @@ class StateStore(SQLBaseStore):
 
     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, hs):
         super(StateStore, self).__init__(hs)
@@ -60,6 +61,13 @@ class StateStore(SQLBaseStore):
             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'",
+        )
 
     @defer.inlineCallbacks
     def get_state_groups_ids(self, room_id, event_ids):