Re: vacuum won't even start

Jean-Christophe Praud <jc@steek.com> writes:
> Indeed, the tables I tried to vacuum have locks on them.
> AccessShareLock belonging to queries which seem sleeping. I tried to
> kill these queries but pg_cancel_backend() has no effect, and the
> process doesn't get the 15 signal.

> How can I get rid of these blocking queries without restarting the
> server ? They are not listed as "waiting" in pg_stat_activity.

Have you tried killing the connected client sessions?

            regards, tom lane