X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (mx2.hub.org [200.46.204.254]) by postgresql.org (Postfix) with ESMTP id 34D4911F653E for ; Thu, 13 Apr 2006 15:00:29 -0300 (ADT) X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Score: -1.53 X-Spam-Level: X-Spam-Status: No, score=-1.53 required=5 tests=[BAYES_00=-2.599, SPF_NEUTRAL=1.069] Received: from postgresql.org ([200.46.204.71]) by localhost (mx2.hub.org [200.46.204.254]) (amavisd-new, port 10024) with ESMTP id dSABqk1ID8Ng for ; Thu, 13 Apr 2006 15:00:26 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from noel.decibel.org (noel.decibel.org [67.100.216.10]) by postgresql.org (Postfix) with ESMTP id C6C3711F6539 for ; Thu, 13 Apr 2006 15:00:25 -0300 (ADT) Received: from [172.16.5.67] (64-132-13-2.gen.twtelecom.net [64.132.13.2]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) by noel.decibel.org (Postfix) with ESMTP id 1DE1D56408 for ; Thu, 13 Apr 2006 13:00:09 -0500 (CDT) Mime-Version: 1.0 (Apple Message framework v749.3) Content-Transfer-Encoding: 7bit Message-Id: <85979594-1CCA-43C5-A8F2-08685CF41ACE@pervasive.com> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed To: Postgresql Performance From: Jim Nasby Subject: Blocks read for index scans Date: Thu, 13 Apr 2006 13:00:07 -0500 X-Mailer: Apple Mail (2.749.3) X-Archive-Number: 200604/309 X-Sequence-Number: 18393 While working on determining a good stripe size for a database, I realized it would be handy to know what the average request size is. Getting this info is a simple matter of joining pg_stat_all_tables and pg_statio_all_tables and doing some math, but there's one issue I've found; it appears that there's no information on how many heap blocks were read in by an index scan. Is there any way to get that info? -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461