Message-ID: <487CBE5E.6030903@zeut.net>
Date: Tue, 15 Jul 2008 11:12:30 -0400
From: "Matthew T. O'Connor" <matthew@zeut.net>
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To: Chris Hoover <revoohc@gmail.com>
CC: "pgsql-admin@postgresql.org Admin" <pgsql-admin@postgresql.org>
Subject: Re: More Autovacuum questions
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Chris Hoover wrote:
> Another question.
> 
> When autovacuum sleeps, does it release the lock it has on the table? 
> 
> What we would like to have happen is for vacuum to work for a while, 
> sleep, and while it is sleeping run an analyze on the table.  We need 
> this due to how quickly our data is changing.  Currently we are running 
> analyze every 5 minutes against the table of question and get a very 
> serious performance hit when vacuum runs due to the index stats getting 
> out of date.  As soon as we rerun analyze after the vacuum happiness 
> returns.
> 
> The pg_total_relation_size for the table in question is 64GB, and as 
> stated above is a very heavily used and modifed table.

As Alvaro already said this is a case where autovacuum still isn't 
great.  Perhaps what you should do here is disable auto-vacumming of the 
table during busy periods and and only have it vacuum at off peak times?