Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id BA08D9FB57B for ; Thu, 1 Mar 2007 16:44:09 -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 12238-09 for ; Thu, 1 Mar 2007 16:44:02 -0400 (AST) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.4 Received: from wx-out-0506.google.com (wx-out-0506.google.com [66.249.82.239]) by postgresql.org (Postfix) with ESMTP id B3B7C9FB511 for ; Thu, 1 Mar 2007 16:44:04 -0400 (AST) Received: by wx-out-0506.google.com with SMTP id i28so545829wxd for ; Thu, 01 Mar 2007 12:44:03 -0800 (PST) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=e9eTyica5faPTki2pSUm9x5f7DC9cTfwarXOAeEBNJ0tzek46LKmwvT4YUypaZgUOuk3apKN6X7CgKr6xiG8fTQsDZXsYzyteVVRMH48I6VEcpd2bLRpKJDh5zP3pIjV0aC4pMrUpiQOYKuilTlop1UDdcBY3LCOWFNADUWNJBc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=t01EVn67zHZBpXw139Boe4jQZw5SL4Z5wXVFTHl0qU5qplpbkBEHa4DGdJcxMGQbUnkiu4FvKeebCVISfhBU49nl/hya6iBml3sc6R1J7qUEdFPdZVC+CL52EeZjN0dmxhGX+kZWeT1oz8MuAIqNtua/h7bfYk61yKgnCLQE4BY= Received: by 10.90.36.17 with SMTP id j17mr908823agj.1172781843534; Thu, 01 Mar 2007 12:44:03 -0800 (PST) Received: by 10.90.116.10 with HTTP; Thu, 1 Mar 2007 12:44:03 -0800 (PST) Message-ID: Date: Thu, 1 Mar 2007 15:44:03 -0500 From: "Alex Deucher" To: pgsql-performance@postgresql.org Subject: strange performance regression between 7.4 and 8.1 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200703/14 X-Sequence-Number: 23419 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? Thanks, Alex