Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 35D719FB79F for ; Tue, 17 Jul 2007 18:44:19 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 11802-01 for ; Tue, 17 Jul 2007 18:44:15 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from pat.uio.no (pat.uio.no [129.240.10.15]) by postgresql.org (Postfix) with ESMTP id D4C209FB55F for ; Tue, 17 Jul 2007 18:44:15 -0300 (ADT) Received: from mail-mx8.uio.no ([129.240.10.38]) by pat.uio.no with esmtp (Exim 4.67) (envelope-from ) id 1IAuq6-0002Ko-Me for pgsql-performance@postgresql.org; Tue, 17 Jul 2007 23:44:14 +0200 Received: from smtp.uio.no ([129.240.10.9] helo=mail-mx8.uio.no) by mail-mx8.uio.no with esmtp (Exim 4.67) (envelope-from ) id 1IAuq6-0005JZ-DL for pgsql-performance@postgresql.org; Tue, 17 Jul 2007 23:44:14 +0200 Received: from 113.80-203-240.nextgentel.com ([80.203.240.113] helo=[10.0.0.128]) by mail-mx8.uio.no with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.67) (envelope-from ) id 1IAuq6-0005JU-7s for pgsql-performance@postgresql.org; Tue, 17 Jul 2007 23:44:14 +0200 Message-ID: <469D382E.6030603@ifi.uio.no> Date: Tue, 17 Jul 2007 23:44:14 +0200 From: Thomas Finneid User-Agent: Thunderbird 1.5.0.12 (X11/20070604) MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: importance of fast disks with pg Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-UiO-SPF-Received: X-UiO-Resend: resent X-UiO-SPF-Received: X-UiO-Spam-info: not spam, SpamAssassin (score=0.1, required=12.0, autolearn=disabled, AWL=0.120) X-UiO-Scanned: 765F2BBC0131D344190E20113EFF2539974CA921 X-UiO-SPAM-Test: remote_host: 129.240.10.9 spam_score: 1 maxlevel 200 minaction 2 bait 0 mail/h: 386 total 2877385 max/h 8345 blacklist 0 greylist 0 ratelimit 0 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200707/203 X-Sequence-Number: 25887 Hi During the somes I did I noticed that it does not necessarily seem to be true that one needs the fastest disks to have a pg system that is fast. It seems to me that its more important to: - choose the correct methods to use for the operation - tune the pg memory settings - tune/disable pg xlog/wal etc It also seems to me that fast disks are more important for db systems of the OLTP type applications with real concurrency of both readers and writes across many, possibly larger, tables etc. Are the above statements close to having any truth in them? regards thomas