Files
synapse/tests
e5ac865661 Fix largest rooms Admin API failing when pg_stats has no common room IDs (#20390)
Fixes #19561

`GET /_synapse/admin/v1/statistics/database/rooms` returns a 500 when
`pg_stats` has no common `room_id` values for one of the tables it
checks. This happens in two cases:

- The table is empty or not yet analyzed, so `pg_stats` has no row for
it.
- No value is more common than the others, so `most_common_vals` is
`NULL`. `event_edges.room_id` hits this on servers where all rows were
written after schema 72 stopped filling the column.

The change skips the table in both cases, since it adds nothing to the
estimate.

Thanks to @christianarielli for finding the cause and suggesting the
fix. They're credited as co-author on the commit.

The new test runs only on Postgres, as the endpoint doesn't support
SQLite. It creates a room, runs `ANALYZE` while `event_push_actions` is
empty and `event_edges.room_id` is all `NULL`, and checks for a 200 with
the room listed. I ran it against Postgres 17.

`event_edges.room_id` isn't written any more, so dropping that table
from the list might make sense. I left that out to keep this PR small.

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---------

Co-authored-by: Christian Arielli <903609+christianarielli@users.noreply.github.com>
Co-authored-by: Eric Eastwood <erice@element.io>
2026-11-13 13:57:50 +01:00
..
2026-09-18 12:00:45 +01:00