Received: from localhost (unknown [200.46.204.183])
	by developer.postgresql.org (Postfix) with ESMTP id A8FE72E006E
	for <pgsql-admin-postgresql.org@developer.postgresql.org>;
	Thu,  1 May 2008 10:59:26 -0300 (ADT)
Received: from developer.postgresql.org ([200.46.204.71])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 22760-01
	for <pgsql-admin-postgresql.org@developer.postgresql.org>;
	Thu,  1 May 2008 10:59:08 -0300 (ADT)
Received: from mx1.hub.org (mx1.hub.org [200.46.208.106])
	by developer.postgresql.org (Postfix) with ESMTP id 6E3A12E0060
	for <pgsql-admin@postgresql.org>; Thu,  1 May 2008 10:59:14 -0300 (ADT)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.5
Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130])
	by mx1.hub.org (Postfix) with ESMTP id 637E0B0890B
	for <pgsql-admin@postgresql.org>; Thu,  1 May 2008 10:59:07 -0300 (ADT)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
	by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id m41DvSip007699;
	Thu, 1 May 2008 09:57:28 -0400 (EDT)
To: Ian Westmacott <ianw@intellivid.com>
cc: Alvaro Herrera <alvherre@commandprompt.com>, pgsql-admin@postgresql.org
Subject: Re: 8.1.8 autovacuum missing databases 
In-reply-to: <1209646882.16174.15.camel@vega.intellivid.com> 
References: <1209499373.18622.47.camel@vega.intellivid.com>
	<20080429203335.GK5652@alvh.no-ip.org>
	<1209503103.18622.68.camel@vega.intellivid.com>
	<20080429211244.GM5652@alvh.no-ip.org>
	<1209560546.5209.12.camel@vega.intellivid.com>
	<20080430161942.GC21286@alvh.no-ip.org>
	<19778.1209572869@sss.pgh.pa.us>
	<1209574908.22509.6.camel@vega.intellivid.com>
	<20185.1209575233@sss.pgh.pa.us>
	<1209576488.22509.9.camel@vega.intellivid.com>
	<22093.1209588237@sss.pgh.pa.us>
	<1209646882.16174.15.camel@vega.intellivid.com>
Comments: In-reply-to Ian Westmacott <ianw@intellivid.com>
	message dated "Thu, 01 May 2008 09:01:22 -0400"
Date: Thu, 01 May 2008 09:57:28 -0400
Message-ID: <7698.1209650248@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200805/6
X-Sequence-Number: 29090

Ian Westmacott <ianw@intellivid.com> writes:
> I imagine if a database's last process time is in the future, that would
> mess up autovacuum's choice algorithm (at the least).  Can I confirm
> this is the problem?  Is there a way to fix it short of dump/restore?

Hmm, that would explain a lot wouldn't it ... except that it looks to
me like your databases have old enough datvacuumxid to force vacuuming
regardless of last_autovac_time.  So I'm not fully convinced.

AFAICS there is no convenient way in 8.1 to examine the per-database
last_autovac_time entries, which'd be needed to confirm this theory.
We should check that just to be sure.  Please do the following:

1. Stop the postmaster.
2. Move the file $PGDATA/global/pgstat.stat somewhere else.
3. Restart the postmaster.
4. Send pgstat.stat as a binary attachment to me or Alvaro.

This will reset all your statistics counters and also the
last_autovac_time settings.  If autovac starts to behave more
normally then we'll know that was it.

> I mentioned earlier that I had two installations like this.  The second
> one doesn't seem to have any time issues.  But in that case the only
> database being skipped is postgres.  Do I need to worry about that?

Is the age() getting unreasonably large for postgres?  It might be
skipping it because there's been no activity.

			regards, tom lane