Re: controlling autovacuum during the day.

From: Michael Fuhr <mike(at)fuhr(dot)org>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: John Lister <john(dot)lister-ps(at)kickstone(dot)com>, pgsql-admin(at)postgresql(dot)org
Subject: Re: controlling autovacuum during the day.
Date: 2008-12-17 15:29:03
Message-ID: 20081217152903.GA37436@winnie.fuhr.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-admin

On Wed, Dec 17, 2008 at 09:47:23AM -0500, Tom Lane wrote:
> "John Lister" <john(dot)lister-ps(at)kickstone(dot)com> writes:
> > Cheers for the quick reply. I've tweaked them quite a bit, but we have quite
> > a few heavily updated tables that i'd like vacuuming to keep them in check.
> > Unfortunately the autovacuum does a FULL vacuum every so often locking the
> > tables for quite a long time, i'd like to move these to the evening if
> > possible.
>
> Huh? Autovacuum *never* does VACUUM FULL.

Perhaps autovacuum is shrinking the table after finding lots of empty
pages at the end, as in what VACUUM VERBOSE is logging here:

INFO: "foo": truncated 11944384 to 8877366 pages

I think this acquires an AccessExclusiveLock. I've seen this take
hours in the case of a table with a lot of empty pages.

--
Michael Fuhr

In response to

Responses

Browse pgsql-admin by date

  From Date Subject
Next Message John Lister 2008-12-17 15:40:36 Re: controlling autovacuum during the day.
Previous Message Alvaro Herrera 2008-12-17 15:28:30 Re: controlling autovacuum during the day.