Received: from localhost (unknown [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 881089FA29E for ; Wed, 5 Sep 2007 13:03:55 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 50995-06-2 for ; Wed, 5 Sep 2007 13:03:50 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from lists.commandprompt.com (host-254.commandprompt.net [207.173.203.254]) by postgresql.org (Postfix) with ESMTP id E7FD09FA30D for ; Wed, 5 Sep 2007 13:03:49 -0300 (ADT) Received: from perhan.alvh.no-ip.org (190-13-142-51.bk13-dsl.surnet.cl [190.13.142.51]) (authenticated bits=0) by lists.commandprompt.com (8.13.7/8.13.6) with ESMTP id l85G3npZ027633; Wed, 5 Sep 2007 09:03:50 -0700 Received: by perhan.alvh.no-ip.org (Postfix, from userid 1000) id 0A8DA47C62; Wed, 5 Sep 2007 12:03:48 -0400 (CLT) Date: Wed, 5 Sep 2007 12:03:48 -0400 From: Alvaro Herrera To: Carlo Stonebanks Cc: pgsql-performance@postgresql.org Subject: Re: Performance on 8CPU's and 32GB of RAM Message-ID: <20070905160347.GG6102@alvh.no-ip.org> References: <20070904230639.GA23731@alvh.no-ip.org> <4F731254987542AF807CA3EDF411D12B@serenity> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F731254987542AF807CA3EDF411D12B@serenity> User-Agent: Mutt/1.5.16 (2007-06-11) X-Virus-Scanned: ClamAV 0.91.1/4161/Wed Sep 5 03:14:19 2007 on projects.commandprompt.com X-Virus-Status: Clean X-Greylist: Sender succeded SMTP AUTH authentication, not delayed by milter-greylist-1.6 (lists.commandprompt.com [192.168.2.159]); Wed, 05 Sep 2007 09:03:51 -0700 (PDT) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200709/54 X-Sequence-Number: 26599 Carlo Stonebanks wrote: > >> It sounds like you will need a huge lot of vacuuming effort to keep up. > Maybe you should lower autovac scale factors so that your tables are > visited more frequently. A vacuum_delay of 40 sounds like too much > though. > << > > Does autovacuum not impede performance while it is vacuuming a table? It causes I/O. Not sure what else you have in mind. vacuum_delay throttles the I/O usage, at the expense of longer vacuum times. -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support