On Fri, 9 Aug 2024 at 02:12, Christophe Pettus <xof@thebuild.com> wrote: > VACUUM FULL takes an exclusive lock on the table that it is operating on. It's possible that a connection becomes blocked on that exclusive lock waiting for the VACUUM FULL to finish, the application sees the connection stopped and fires up another one (this is common in container-based applications), that one blocks... until all of the connections are full of queries waiting on that VACUUM FULL.
I also imagine this is the cause. One way to test would be to do: BEGIN; LOCK TABLE <name of table>; and see if the connections pile up in a similar way to when the VACUUM FULL command is used.
David
Thanks folks. David really straight-forward way to test. I validated this, when I lock the two tables involved in the benchmark the connections are constantly growing until they reach the `max_connections`
