Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id 536DE1337B6C for ; Wed, 27 Oct 2010 19:37:44 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 57915-08 for ; Wed, 27 Oct 2010 22:37:37 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outbound.afilias.info (outbound.afilias.info [69.46.124.26]) by mail.postgresql.org (Postfix) with ESMTP id 2E6121337B63 for ; Wed, 27 Oct 2010 19:37:37 -0300 (ADT) Message-ID: <4CC8A9A3.7060901@ca.afilias.info> Date: Wed, 27 Oct 2010 18:37:23 -0400 From: Brad Nicholson User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.11) Gecko/20101013 Thunderbird/3.1.5 MIME-Version: 1.0 To: Tom Lane CC: Greg Smith , =?ISO-8859-1?Q?Andr=E9_Volpato?= , pgsql-performance@postgresql.org Subject: Re: AIX slow buffer reads References: <1141414014.10692.1288199109474.JavaMail.root@zimbra01a> <4CC87C69.5070301@2ndquadrant.com> <26542.1288210215@sss.pgh.pa.us> In-Reply-To: <26542.1288210215@sss.pgh.pa.us> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated: True X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-4.21 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201010/520 X-Sequence-Number: 40938 On 10/27/2010 4:10 PM, Tom Lane wrote: > Greg Smith writes: >> André Volpato wrote: >>> I disabled effective_io_concurrency at AIX but it made no changes on bitmap index times. >> Brad's point is that it probably doesn't do anything at all on AIX, and >> is already disabled accordingly. > AFAICT from googling, AIX does have posix_fadvise, though maybe it > doesn't do anything useful ... > > regards, tom lane If there is an easy way to check if it does do anything useful? If so, I can check it out. -- Brad Nicholson 416-673-4106 Database Administrator, Afilias Canada Corp.