Nikhil Shetty <nikhil.dba04@gmail.com> writes:
> I have done a setup to run vacuumdb with 8 parallel jobs daily. It has been
> running quite well.
Apparently not all that well, if it failed to keep us out of an
autovacuum-to-prevent-wraparound situation. I suppose you had autovacuum
disabled because you thought this lashup was sufficient?
> Just today I saw there is an aggressive autovacuum process running(to
> prevent wraparound) on one of the table. vacuumdb which started later
> spawned the 8 connections. One connection (doing vacuum on the table on
> which an aggressive autovacuum is running) is waiting for "autovacuum(to
> prevent wraparound)" to complete while the other 7 connections are just
> sitting idle.
> I am okay that one connection is waiting since an aggressive autovacuum is
> running on that table but how come other connections have not released the
> sesion yet? Any reason for this?
Perhaps this is the last remaining table so vacuumdb has nothing
else for them to do.
regards, tom lane