X-Original-To: pgsql-hackers-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 7524B529F9 for ; Thu, 28 Jul 2005 08:49:56 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 27592-07 for ; Thu, 28 Jul 2005 11:49:45 +0000 (GMT) Received: from stark.xeocode.com (stark.xeocode.com [216.58.44.227]) by svr1.postgresql.org (Postfix) with ESMTP id DA193529EA for ; Thu, 28 Jul 2005 08:49:44 -0300 (ADT) Received: from localhost ([127.0.0.1] helo=stark.xeocode.com) by stark.xeocode.com with smtp (Exim 3.36 #1 (Debian)) id 1Dy6tF-0007uU-00; Thu, 28 Jul 2005 07:49:29 -0400 To: josh@agliodbs.com Cc: pgsql-hackers@postgresql.org Subject: Re: wal_buffer tests in References: <200507271330.02083.josh@agliodbs.com> In-Reply-To: <200507271330.02083.josh@agliodbs.com> From: Greg Stark Organization: The Emacs Conspiracy; member since 1992 Date: 28 Jul 2005 07:49:29 -0400 Message-ID: <87oe8n881i.fsf@stark.xeocode.com> Lines: 16 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.003 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200507/1045 X-Sequence-Number: 71097 Josh Berkus writes: > Folks, > > I ran a wal_buffer test series. It appears that increasing the > wal_buffers is indeed very important for OLTP applications, potentially > resulting in as much as a 15% average increase in transaction processing. > What's interesting is that this is not just true for 8.1, it's true for > 8.0.3 as well. You have wal_buffer set to 2048? That's pretty radical compared to the default of just 5. Your tests shows you had to go to this large a value to see the maximum effect? -- greg