How to check if my queries are being blocked by other queries?

Last edited: 1/17/2025

You can set a lock monitor view to help investigate these.

Once you run the query that takes a long time to complete, you can go in the dashboard (or select from this view below) to check what are the blocks.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
create view  public.lock_monitor asselect  coalesce(    blockingl.relation::regclass::text,    blockingl.locktype  ) as locked_item,  now() - blockeda.query_start as waiting_duration,  blockeda.pid as blocked_pid,  blockeda.query as blocked_query,  blockedl.mode as blocked_mode,  blockinga.pid as blocking_pid,  blockinga.query as blocking_query,  blockingl.mode as blocking_modefrom  pg_locks blockedl  join pg_stat_activity blockeda on blockedl.pid = blockeda.pid  join pg_locks blockingl on (    blockingl.transactionid = blockedl.transactionid    or blockingl.relation = blockedl.relation    and blockingl.locktype = blockedl.locktype  )  and blockedl.pid <> blockingl.pid  join pg_stat_activity blockinga on blockingl.pid = blockinga.pid  and blockinga.datid = blockeda.datidwhere  not blockedl.granted  and blockinga.datname = current_database();