Re: [GENERAL] Non-overlapping updates blocking each other - Mailing list pgsql-general

Have you done and EXPLAIN on each of the updates?

More than likely, the optimizer has determined that a table scan is best, in which case it will use a table lock.

That means one updates will be blocking each other.

You can also execute the following query and check the wait_event_type to verify.

SELECT c.datname,
       c.pid as pid,
       c.client_addr,
       c.usename as user,
       c.query,
       c.wait_event,
       c.wait_event_type,
      l.pid as blocked_by,
       c.query_start,
       current_timestamp - c.query_start as duration
  FROM pg_stat_activity c
  LEFT JOIN pg_locks l1 ON (c.pid = l1.pid and not l1.granted)
  LEFT JOIN pg_locks l2 on (l1.relation = l2.relation and l2.granted)
  LEFT JOIN pg_stat_activity l ON (l2.pid = l.pid)
  LEFT JOIN pg_stat_user_tables t ON (l1.relation = t.relid)
 WHERE pg_backend_pid() <> c.pid
ORDER BY datname,
         query_start;

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