Re: Problem with pg_upgrade?

Bruce Momjian wrote:
> > It does seem possible that that could happen, but I'm not sure exactly
> > what would be causing autovacuum to fire in the first place.  It
> > wouldn't have to be triggered by the anti-wraparound machinery - if
> > the table appeared to be in need of vacuuming, then we'd vacuum it,
> > discover that is was empty, and update relfrozenxid.  Hmm... could it
> > fire just because the table has no stats?  But if that were the case
> > you'd think we'd be seeing this more often.
> 
> Well, autovacuum=off, so it should only run in freeze mode, and I can't
> see how that could happen.  I am thinking I have to study autovacuum.c.
> 
> I wonder if datfrozenxid could be incremented because the database is
> originally empty.  It would just need to scan pg_class, not actually
> vacuum anything.  I wonder if we do that.  The bottom line is I am
> hanging too much on autovacuum_freeze_max_age causing autovacuum to do
> nothing.

What if we allow autovacuum_max_workers to be set to zero;  the current
minimum is one.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +