Skip to content
This repository has been archived by the owner on Apr 26, 2024. It is now read-only.

Speed up membership queries for users with forgotten rooms #15385

Merged
merged 5 commits into from
Apr 4, 2023
Merged
Show file tree
Hide file tree
Changes from 4 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions changelog.d/15385.misc
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Speed up membership queries for users with forgotten rooms.
12 changes: 11 additions & 1 deletion synapse/storage/databases/main/roommember.py
Original file line number Diff line number Diff line change
Expand Up @@ -419,7 +419,11 @@ async def get_rooms_for_local_user_where_membership_is(
)

# Now we filter out forgotten and excluded rooms
rooms_to_exclude = await self.get_forgotten_rooms_for_user(user_id)
rooms_to_exclude: AbstractSet[str] = set()

# Users can't forget joined/invited rooms, so we skip the check for such look ups.
if not all(m in (Membership.JOIN, Membership.INVITE) for m in membership_list):
erikjohnston marked this conversation as resolved.
Show resolved Hide resolved
rooms_to_exclude = await self.get_forgotten_rooms_for_user(user_id)

if excluded_rooms is not None:
# Take a copy to avoid mutating the in-cache set
Expand Down Expand Up @@ -1391,6 +1395,12 @@ def __init__(
columns=["user_id", "room_id"],
where_clause="forgotten = 1",
)
self.db_pool.updates.register_background_index_update(
"room_membership_user_room_index",
index_name="room_membership_user_room_idx",
table="room_memberships",
columns=["user_id", "room_id"],
)
Comment on lines +1398 to +1403
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

What's the query plan look like with the index added?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

 Group  (cost=0.12..8.73 rows=1 width=68)
   Group Key: m.room_id, m.user_id
   ->  Index Only Scan using room_memberships_user_room_forgotten on room_memberships m  (cost=0.12..4.14 rows=1 width=60)
         Index Cond: (user_id = '@erikj:jki.re'::text)
   SubPlan 1
     ->  Aggregate  (cost=4.58..4.59 rows=1 width=8)
           ->  Index Only Scan using test_rm_forgotten on room_memberships  (cost=0.56..4.57 rows=1 width=0)
                 Index Cond: ((user_id = m.user_id) AND (room_id = m.room_id))

On jki.re


async def _background_add_membership_profile(
self, progress: JsonDict, batch_size: int
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,19 @@
/* Copyright 2023 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.
*/

-- Add an index to `room_membership(user_id, room_id)` to make querying for
-- forgotten rooms faster.
INSERT INTO background_updates (ordering, update_name, progress_json) VALUES
(7403, 'room_membership_user_room_index', '{}');