X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 996D69DCA16 for ; Tue, 21 Mar 2006 17:20:41 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 67550-07 for ; Tue, 21 Mar 2006 17:20:42 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from mx1.surnet.cl (mx1.surnet.cl [216.155.73.180]) by postgresql.org (Postfix) with ESMTP id 5A93F9DC809 for ; Tue, 21 Mar 2006 17:20:38 -0400 (AST) Received: from unknown (HELO cluster.surnet.cl) ([216.155.73.165]) by mx1.surnet.cl with ESMTP; 21 Mar 2006 17:20:39 -0400 X-IronPort-AV: i="4.03,116,1141614000"; d="scan'208"; a="47990841:sNHT3919724136" Received: from alvh.no-ip.org (201.220.122.38) by cluster.surnet.cl (7.0.043) (authenticated as alvherre@surnet.cl) id 43A978FD00B63D51; Tue, 21 Mar 2006 17:20:38 -0400 Received: by alvh.no-ip.org (Postfix, from userid 1000) id A6EF8C3A2D0; Tue, 21 Mar 2006 17:20:38 -0400 (CLT) Date: Tue, 21 Mar 2006 17:20:38 -0400 From: Alvaro Herrera To: Ron Cc: Mikael Carneholm , pgsql-performance@postgresql.org Subject: Re: Migration study, step 1: bulk write performance Message-ID: <20060321212038.GD17121@surnet.cl> Mail-Followup-To: Ron , Mikael Carneholm , pgsql-performance@postgresql.org References: <7F10D26ECFA1FB458B89C5B4B0D72C2B088286@sesrv12.wirelesscar.com> <1142973890.24487.510.camel@localhost.localdomain> <7.0.1.0.2.20060320161133.03a0b5a8@earthlink.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7.0.1.0.2.20060320161133.03a0b5a8@earthlink.net> User-Agent: Mutt/1.5.11+cvs20060126 X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=1.695 required=5 tests=[AWL=-0.224, DNS_FROM_RFC_ABUSE=0.479, DNS_FROM_RFC_POST=1.44] X-Spam-Score: 1.695 X-Spam-Level: * X-Archive-Number: 200603/430 X-Sequence-Number: 17867 Ron wrote: > IIRC, Josh Berkus did some benches that suggests in pg 8.x a value of > 64 - 256 is best for checkpoint_segments as long as you have the RAM > available. I think you are confusing checkpoint_segments with wal_buffers. checkpoint_segments certainly has little to do with available RAM! -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.