Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 2BD67633080 for ; Thu, 7 Jan 2010 02:39:51 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 62929-08 for ; Thu, 7 Jan 2010 06:39:38 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.17.9]) by mail.postgresql.org (Postfix) with ESMTP id 3A72E632F30 for ; Thu, 7 Jan 2010 02:39:40 -0400 (AST) Received: from [192.168.1.3] (pool-96-244-14-10.bltmmd.fios.verizon.net [96.244.14.10]) by mrelayeu.kundenserver.de (node=mrbap2) with ESMTP (Nemesis) id 0MGoe9-1NfkSD1TBR-00DikG; Thu, 07 Jan 2010 07:39:38 +0100 Message-ID: <4B4581A3.1050401@2ndquadrant.com> Date: Thu, 07 Jan 2010 01:39:31 -0500 From: Greg Smith User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Jesper Krogh CC: Ron Mayer , pgsql-performance@postgresql.org Subject: Re: Digesting explain analyze References: <4B44E02A.6080109@krogh.cc> <4B44EC89.7060200@cheapcomplexdevices.com> <4B457AD4.8090405@krogh.cc> In-Reply-To: <4B457AD4.8090405@krogh.cc> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V01U2FsdGVkX19JbMPbl1IyaLO8fRJxCUb9IsLrBosVtfKkbQ5 h4gHu15BDjXaxTRtb7CQqTXZ9sJoTDHyNXCHy1BO1MipIFfSLq nmCvPnMBTYPPhSDRho5sbc5Kx06dFRD X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.233 tagged_above=-10 required=5 tests=AWL=-1.048, BAYES_40=-0.185 X-Spam-Level: X-Archive-Number: 201001/74 X-Sequence-Number: 36954 Jesper Krogh wrote: > Is it possible to get PG to tell me, how many rows that fits in a > disk-page. All columns are sitting in "plain" storage according to \d+ > on the table. > select relname,round(reltuples / relpages) as "avg_rows_per_page" from pg_class where relpages > 0; -- Greg Smith 2ndQuadrant Baltimore, MD PostgreSQL Training, Services and Support greg@2ndQuadrant.com www.2ndQuadrant.com