Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VQgL8-0002pI-PL for pgsql-performance@arkaria.postgresql.org; Mon, 30 Sep 2013 16:28:55 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1VQgL7-00087p-Dg for pgsql-performance@arkaria.postgresql.org; Mon, 30 Sep 2013 16:28:53 +0000 Received: from makus.postgresql.org ([2001:4800:7903:4::125]) by malur.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VQgL6-00087j-FU for pgsql-performance@postgresql.org; Mon, 30 Sep 2013 16:28:52 +0000 Received: from mail01.pnet.xcon.it ([62.48.53.71]) by makus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VQgL0-0004Wt-IW for pgsql-performance@postgresql.org; Mon, 30 Sep 2013 16:28:51 +0000 Received: from localhost (av.pnet.xcon.it [10.68.1.18]) by mail01.pnet.xcon.it (Postfix) with ESMTP id C7F8F301BF48D; Mon, 30 Sep 2013 18:28:45 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at av Received: from mail01.pnet.xcon.it ([10.68.1.19]) by localhost (av.pnet.xcon.it [10.68.1.18]) (amavisd-new, port 10024) with LMTP id DtSqvru+PSr3; Mon, 30 Sep 2013 18:27:59 +0200 (CEST) Received: from bnc1.pnet.xcon.it (bnc1.pnet.xcon.it [10.68.1.23]) by mail01.pnet.xcon.it (Postfix) with ESMTP id A6E24301BF2F1; Mon, 30 Sep 2013 18:28:45 +0200 (CEST) Received: from localhost (av.pnet.xcon.it [10.68.1.18]) by bnc1.pnet.xcon.it (Postfix) with ESMTP id 9CA1F1022E36; Mon, 30 Sep 2013 18:28:45 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at av Received: from bnc1.pnet.xcon.it ([10.68.1.23]) by localhost (av.pnet.xcon.it [10.68.1.18]) (amavisd-new, port 10024) with LMTP id x23UC2HvL1sR; Mon, 30 Sep 2013 18:27:59 +0200 (CEST) Received: from [192.168.0.144] (unknown [83.149.163.202]) (Authenticated sender: giuseppe.broccolo@2ndquadrant.it) by bnc1.pnet.xcon.it (Postfix) with ESMTPSA id EEFE91022E35; Mon, 30 Sep 2013 18:28:44 +0200 (CEST) Message-ID: <5249A733.5070904@2ndquadrant.it> Date: Mon, 30 Sep 2013 18:30:43 +0200 From: Giuseppe Broccolo User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Xenofon Papadopoulos CC: postgres performance list Subject: Re: pg_statio_all_tables columns References: <52498D71.8010002@2ndquadrant.it> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -0.0 (/) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org Il 30/09/2013 16:41, Xenofon Papadopoulos ha scritto: > Should this ratio stay low even in the case of a write-heavy table? Yes, in my opinion. Before data manipolation, database pages are moved on the shared buffer. heap_blks_read and heap_blks_hit are involved in those operations, not directly in data persistance on hard driver. Giuseppe. -- Giuseppe Broccolo - 2ndQuadrant Italy PostgreSQL Training, Services and Support giuseppe.broccolo@2ndQuadrant.it | www.2ndQuadrant.it -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance