Re: autovacuum not prioritising for-wraparound tables

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Peter Eisentraut <peter_e@gmx.net>, Christopher Browne <cbbrowne@gmail.com>, Heikki Linnakangas <hlinnakangas@vmware.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2013-01-25T16:44:49Z
Lists: pgsql-hackers
Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Peter Eisentraut escribi:
>> Autovacuum has existed for N years and nobody complained about this
>> until just now, so I don't see a strong justification for backpatching.

> I disagree about people not complaining.  Maybe the complaints have not
> been specifically about the wraparound stuff and toast tables, but for
> sure there have been complaints about autovacuum not giving more
> priority to tables that need work more urgently.

FWIW, I don't see that this is too scary to back-patch.  It's unlikely
to make things worse than the current coding, which is more or less
pg_class tuple order.

I do suggest that it might be wise not to try to squeeze it into the
early-February update releases.  Put it in master as soon as we agree
on the behavior, then back-patch after the next updates.  That will
give us a couple months' testing, rather than a few days, before it
hits any release tarballs.

			regards, tom lane


Commits

  1. COPY FREEZE and mark committed on fresh tables.

  2. Add vacuum_freeze_table_age GUC option, to control when VACUUM should