Received: from localhost (unknown [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 702032E0191 for ; Fri, 30 Nov 2007 18:34:22 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 38296-01 for ; Fri, 30 Nov 2007 18:34:15 -0400 (AST) Received: from lists.commandprompt.com (host-159.commandprompt.net [207.173.203.159]) by postgresql.org (Postfix) with ESMTP id 2187C2E016E for ; Fri, 30 Nov 2007 18:34:18 -0400 (AST) Received: from perhan.alvh.no-ip.org (200-126-98-252.bk7-dsl.surnet.cl [200.126.98.252]) (authenticated bits=0) by lists.commandprompt.com (8.13.8/8.13.8) with ESMTP id lAUMY3OW001667 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 30 Nov 2007 14:34:12 -0800 Received: by perhan.alvh.no-ip.org (Postfix, from userid 1000) id AE98047C69; Fri, 30 Nov 2007 19:34:02 -0300 (CLST) Date: Fri, 30 Nov 2007 19:34:02 -0300 From: Alvaro Herrera To: "Joshua D. Drake" Cc: Tom Lane , "Jonah H. Harris" , "Campbell, Lance" , posgres support Subject: Re: Enhancement request Message-ID: <20071130223402.GG3175@alvh.no-ip.org> References: <36e682920711301218m703b3c67s6f547fd7b9b60e7c@mail.gmail.com> <7099.1196458205@sss.pgh.pa.us> <36e682920711301332q1cce5db9qe44fb068fcd5608d@mail.gmail.com> <7341.1196459304@sss.pgh.pa.us> <20071130140005.18521c54@jd-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20071130140005.18521c54@jd-laptop> User-Agent: Mutt/1.5.16 (2007-06-11) X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0 (lists.commandprompt.com [207.173.203.159]); Fri, 30 Nov 2007 14:34:12 -0800 (PST) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200711/269 X-Sequence-Number: 27512 Joshua D. Drake escribió: > Autovacuum is a great utility for many workloads but even with the > upcoming changes I will continually find myself turning off autovacuum > for specific relations just so I can turn around and turn on vacuum > within cron for others. > > The multi-worker autovacuum is a great new addition to help part of > that problem (starvation) but it is not help against the other > (resource consumption, specifically IO). Huh, autovac will consume exactly the same amount of I/O as a user-induced vacuum, so I don't see your point. Multiworker autovac hasn't been tried on your customer's servers yet. It may well turn out to be that it is possible to let it do its work even on the high-update tables or large tables that you currently use cron for. It might be just a matter of tuning the knobs. Remember, we're not adding VACUUM SCHEMA in 8.2 so it doesn't make any sense to try to compare it against the old autovac. And you can bet that in 8.4 autovac will have even more goodies. -- Alvaro Herrera Valdivia, Chile ICBM: S 39º 49' 18.1", W 73º 13' 56.4" "This is a foot just waiting to be shot" (Andrew Dunstan)