Subject: Re: 8.1.8 autovacuum missing databases
From: Ian Westmacott <ianw@intellivid.com>
To: Alvaro Herrera <alvherre@commandprompt.com>
Cc: pgsql-admin@postgresql.org
In-Reply-To: <20080429211244.GM5652@alvh.no-ip.org>
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Organization: IntelliVid Corp.
Date: Wed, 30 Apr 2008 09:02:26 -0400
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On Tue, 2008-04-29 at 17:12 -0400, Alvaro Herrera wrote:
> Can you verify whether age(pg_database.datfrozenxid) is shrinking after
> vacuuming?  If the age() of a database is higher than the applicable
> max_freeze_age, then it will always be chosen.

One of the databases is about 1.5TB, so that could take a while.
Anything else I could look at in the meantime?  The age of these
databases right now is about 290039577.  Also, autovacuum doesn't always
choose the same DB, it alternates between template1 and one of mine --
going back through a couple of months of logs I don't see it ever
choosing the same one twice in a row.

I'll note that I have 5 of these essentially identical systems (same
hardware/software platform, databases, configuration, and load).  Two of
them have this issue (autovacuum processing multiple databases, but not
all) and the other three don't.  A commonality between the two that have
this issue is that template1 is processed but postgres is not.  One of
the two is processing the 1.5TB DB but the other is not.

Thanks,

	--Ian