Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 7DA4D1337BC8 for ; Wed, 13 Apr 2011 21:37:32 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024) with ESMTP id 27081-04-7 for ; Thu, 14 Apr 2011 00:37:25 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from spinlock.commandprompt.com (host-215.commandprompt.net [207.173.203.215]) by mail.postgresql.org (Postfix) with ESMTP id 3D66C1337C0F for ; Wed, 13 Apr 2011 21:37:13 -0300 (ADT) Received: from localhost (localhost [127.0.0.1]) by spinlock.commandprompt.com (Postfix) with ESMTP id 2DC3234804D for ; Wed, 13 Apr 2011 17:37:08 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at commandprompt.com Received: from spinlock.commandprompt.com ([127.0.0.1]) by localhost (spinlock.commandprompt.com.commandprompt.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id MZo-g1zU1C4Y for ; Wed, 13 Apr 2011 17:37:06 -0700 (PDT) Received: from [192.168.1.100] (71-94-248-62.dhcp.mdfd.or.charter.com [71.94.248.62]) by spinlock.commandprompt.com (Postfix) with ESMTPSA id 4665A34804A for ; Wed, 13 Apr 2011 17:37:06 -0700 (PDT) Message-ID: <4DA641B1.4060707@commandprompt.com> Date: Wed, 13 Apr 2011 17:37:05 -0700 From: "Joshua D. Drake" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.14) Gecko/20110223 Lightning/1.0b2 Thunderbird/3.1.8 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: Performance References: <20110412171855.GA14292@tux> <4DA496FA.3070908@fuzzy.cz> <8F22D592-23C1-4A3C-94A5-48363332ADD3@darkstatic.com> <4DA4BFA2.5060601@fuzzy.cz> <4DA4D40A.4010200@fuzzy.cz> <4DA56DA8020000250003C783@gw.wicourts.gov> <1809.1302739389@sss.pgh.pa.us> In-Reply-To: <1809.1302739389@sss.pgh.pa.us> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.9 tagged_above=-10 required=5 tests=BAYES_00=-1.9 X-Spam-Level: X-Archive-Number: 201104/206 X-Sequence-Number: 43268 On 04/13/2011 05:03 PM, Tom Lane wrote: > That 4:1 ratio is based on some rather extensive experimentation that > I did back in 2000. In the interim, disk transfer rates have improved > quite a lot more than disk seek times have, and the CPU cost to process > a page's worth of data has also improved compared to the seek time. My experience is that at least a 1/1 is more appropriate. JD