Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id CAEB99FB5CB for ; Thu, 1 Mar 2007 16:49:56 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-new, port 10024) with ESMTP id 13634-01 for ; Thu, 1 Mar 2007 16:49:50 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from lists.commandprompt.com (host-254.commandprompt.net [207.173.203.254]) by postgresql.org (Postfix) with ESMTP id D55B09FB461 for ; Thu, 1 Mar 2007 16:49:51 -0400 (AST) Received: from [192.168.1.50] (or-67-76-146-141.sta.embarqhsd.net [67.76.146.141]) (authenticated bits=0) by lists.commandprompt.com (8.13.7/8.13.6) with ESMTP id l21Knq8W001597 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 1 Mar 2007 12:49:53 -0800 Message-ID: <45E73C90.2080206@commandprompt.com> Date: Thu, 01 Mar 2007 12:50:24 -0800 From: "Joshua D. Drake" Organization: Command Prompt, Inc. User-Agent: Thunderbird 1.5.0.9 (X11/20070103) MIME-Version: 1.0 To: Alex Deucher CC: pgsql-performance@postgresql.org Subject: Re: strange performance regression between 7.4 and 8.1 References: In-Reply-To: X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV version 0.88.5, clamav-milter version 0.88.5 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]); Thu, 01 Mar 2007 12:49:53 -0800 (PST) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.073 tagged_above=0 required=5 tests=AWL, BAYES_50, FORGED_RCVD_HELO X-Spam-Level: X-Archive-Number: 200703/15 X-Sequence-Number: 23420 Alex Deucher wrote: > Hello, > > I have noticed a strange performance regression and I'm at a loss as > to what's happening. We have a fairly large database (~16 GB). The > original postgres 7.4 was running on a sun v880 with 4 CPUs and 8 GB > of ram running Solaris on local scsi discs. The new server is a sun > Opteron box with 4 cores, 8 GB of ram running postgres 8.1.4 on Linux > (AMD64) on a 4 Gbps FC SAN volume. When we created the new database > it was created from scratch rather than copying over the old one, > however the table structure is almost identical (UTF8 on the new one > vs. C on the old). The problem is queries are ~10x slower on the new > hardware. I read several places that the SAN might be to blame, but > testing with bonnie and dd indicates that the SAN is actually almost > twice as fast as the scsi discs in the old sun server. I've tried > adjusting just about every option in the postgres config file, but > performance remains the same. Any ideas? Vacuum? Analayze? default_statistics_target? How many shared_buffers? effective_cache_size? work_mem? Sincerely, Joshua D. Drake > > Thanks, > > Alex > > ---------------------------(end of broadcast)--------------------------- > TIP 3: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faq > -- === The PostgreSQL Company: Command Prompt, Inc. === Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240 Providing the most comprehensive PostgreSQL solutions since 1997 http://www.commandprompt.com/ Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate PostgreSQL Replication: http://www.commandprompt.com/products/