## Some useful SQL queries for Synapse Admins

## Size of full matrix db

`SELECT pg_size_pretty( pg_database_size( 'matrix' ) );`

### Result example:

    pg_size_pretty
    ----------------
     6420 MB
    (1 row)

## Show top 20 larger rooms by state events count

    SELECT r.name, s.room_id, s.current_state_events
      FROM room_stats_current s
      LEFT JOIN room_stats_state r USING (room_id)
      ORDER BY current_state_events DESC
      LIMIT 20;

and by state_group_events count:

    SELECT rss.name, s.room_id, count(s.room_id) FROM state_groups_state s
    LEFT JOIN room_stats_state rss USING (room_id)
    GROUP BY s.room_id, rss.name
    ORDER BY count(s.room_id) DESC
    LIMIT 20;

plus same, but with join removed for performance reasons:

    SELECT s.room_id, count(s.room_id) FROM state_groups_state s
    GROUP BY s.room_id
    ORDER BY count(s.room_id) DESC
    LIMIT 20;

## Show top 20 larger tables by row count

    SELECT relname, n_live_tup as rows
      FROM pg_stat_user_tables
      ORDER BY n_live_tup DESC
      LIMIT 20;

This query is quick, but may be very approximate, for exact number of rows use `SELECT COUNT(*) FROM <table_name>`.

### Result example:

    state_groups_state - 161687170
    event_auth - 8584785
    event_edges - 6995633
    event_json - 6585916
    event_reference_hashes - 6580990
    events - 6578879
    received_transactions - 5713989
    event_to_state_groups - 4873377
    stream_ordering_to_exterm - 4136285
    current_state_delta_stream - 3770972
    event_search - 3670521
    state_events - 2845082
    room_memberships - 2785854
    cache_invalidation_stream - 2448218
    state_groups - 1255467
    state_group_edges - 1229849
    current_state_events - 1222905
    users_in_public_rooms - 364059
    device_lists_stream - 326903
    user_directory_search - 316433

## Show top 20 rooms by new events count in last 1 day:

    SELECT e.room_id, r.name, COUNT(e.event_id) cnt FROM events e
    LEFT JOIN room_stats_state r USING (room_id)
    WHERE e.origin_server_ts >= DATE_PART('epoch', NOW() - INTERVAL '1 day') * 1000 GROUP BY e.room_id, r.name ORDER BY cnt DESC LIMIT 20;

## Show top 20 users on homeserver by sent events (messages) at last month:

    SELECT user_id, SUM(total_events)
       FROM user_stats_historical
       WHERE TO_TIMESTAMP(end_ts/1000) AT TIME ZONE 'UTC' > date_trunc('day', now() - interval '1 month')
       GROUP BY user_id
       ORDER BY SUM(total_events) DESC
       LIMIT 20;

## Show last 100 messages from needed user, with room names:

    SELECT e.room_id, r.name, e.event_id, e.type, e.content, j.json FROM events e
      LEFT JOIN event_json j USING (room_id)
      LEFT JOIN room_stats_state r USING (room_id)
      WHERE sender = '@LOGIN:example.com'
      AND e.type = 'm.room.message'
      ORDER BY stream_ordering DESC
      LIMIT 100;

## Show top 20 larger tables by storage size

    SELECT nspname || '.' || relname AS "relation",
        pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
      FROM pg_class C
      LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
      WHERE nspname NOT IN ('pg_catalog', 'information_schema')
        AND C.relkind <> 'i'
        AND nspname !~ '^pg_toast'
      ORDER BY pg_total_relation_size(C.oid) DESC
      LIMIT 20;

### Result example:

    public.state_groups_state - 27 GB
    public.event_json - 9855 MB
    public.events - 3675 MB
    public.event_edges - 3404 MB
    public.received_transactions - 2745 MB
    public.event_reference_hashes - 1864 MB
    public.event_auth - 1775 MB
    public.stream_ordering_to_exterm - 1663 MB
    public.event_search - 1370 MB
    public.room_memberships - 1050 MB
    public.event_to_state_groups - 948 MB
    public.current_state_delta_stream - 711 MB
    public.state_events - 611 MB
    public.presence_stream - 530 MB
    public.current_state_events - 525 MB
    public.cache_invalidation_stream - 466 MB
    public.receipts_linearized - 279 MB
    public.state_groups - 160 MB
    public.device_lists_remote_cache - 124 MB
    public.state_group_edges - 122 MB

## Show rooms with names, sorted by events in this rooms

`echo "select event_json.room_id,room_stats_state.name from event_json,room_stats_state where room_stats_state.room_id=event_json.room_id" | psql synapse | sort | uniq -c | sort -n`

### Result example:

       9459  !FPUfgzXYWTKgIrwKxW:matrix.org              | This Week in Matrix
       9459  !FPUfgzXYWTKgIrwKxW:matrix.org              | This Week in Matrix (TWIM)
      17799  !iDIOImbmXxwNngznsa:matrix.org              | Linux in Russian
      18739  !GnEEPYXUhoaHbkFBNX:matrix.org              | Riot Android
      23373  !QtykxKocfZaZOUrTwp:matrix.org              | Matrix HQ
      39504  !gTQfWzbYncrtNrvEkB:matrix.org              | ru.[matrix]
      43601  !iNmaIQExDMeqdITdHH:matrix.org              | Riot
      43601  !iNmaIQExDMeqdITdHH:matrix.org              | Riot Web/Desktop

## Lookup room state info by list of room_id

    SELECT rss.room_id, rss.name, rss.canonical_alias, rss.topic, rss.encryption, rsc.joined_members, rsc.local_users_in_room, rss.join_rules
    FROM room_stats_state rss
    LEFT JOIN room_stats_current rsc USING (room_id)
    WHERE room_id IN (WHERE room_id IN (
     '!OGEhHVWSdvArJzumhm:matrix.org',
     '!YTvKGNlinIzlkMTVRl:matrix.org'
    )