Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 320BB632B5D for ; Thu, 2 Sep 2010 13:49:19 -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 59535-07 for ; Thu, 2 Sep 2010 16:49:08 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by mail.postgresql.org (Postfix) with ESMTP id C2FC16326F3 for ; Thu, 2 Sep 2010 13:49:07 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id o82Gn650025774; Thu, 2 Sep 2010 12:49:06 -0400 (EDT) To: A J cc: Scott Marlowe , Kevin Grittner , pgsql-admin@postgresql.org Subject: Re: Confused by 'timing' results In-reply-to: <529329.89885.qm@web120007.mail.ne1.yahoo.com> References: <788866.21140.qm@web120020.mail.ne1.yahoo.com> <4C7D00330200002500034ED2@gw.wicourts.gov> <19320.56933.qm@web120013.mail.ne1.yahoo.com> <529329.89885.qm@web120007.mail.ne1.yahoo.com> Comments: In-reply-to A J message dated "Thu, 02 Sep 2010 09:12:59 -0700" Date: Thu, 02 Sep 2010 12:49:06 -0400 Message-ID: <25773.1283446146@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.91 tagged_above=-10 required=5 tests=BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201009/17 X-Sequence-Number: 35561 A J writes: > The problem I am now facing in using log_min_duration_statement is that all the > clients have to write to a single log file in the pg_log directory. So they have > to wait for the other writes to happen before completing their write. This seems > to be reason why the measured duration in the log file (for several concurrent > clients) is way more, infact much more than what was measured by psql timing > from the client side. Do you have any actual evidence for that being the problem, as opposed to some other effect? Because I don't recall anybody else complaining about this. Personally I'd wonder for example about whether the server has a really slow gettimeofday()... regards, tom lane