Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 8CCE41337B6C for ; Wed, 27 Oct 2010 17:10:28 -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 79315-03 for ; Wed, 27 Oct 2010 20:10:22 +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 E0A321337B5B for ; Wed, 27 Oct 2010 17:10:20 -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 o9RKAFae026543; Wed, 27 Oct 2010 16:10:15 -0400 (EDT) To: Greg Smith cc: =?UTF-8?B?QW5kcsOpIFZvbHBhdG8=?= , Brad Nicholson , pgsql-performance@postgresql.org Subject: Re: AIX slow buffer reads In-reply-to: <4CC87C69.5070301@2ndquadrant.com> References: <1141414014.10692.1288199109474.JavaMail.root@zimbra01a> <4CC87C69.5070301@2ndquadrant.com> Comments: In-reply-to Greg Smith message dated "Wed, 27 Oct 2010 15:24:25 -0400" Date: Wed, 27 Oct 2010 16:10:15 -0400 Message-ID: <26542.1288210215@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: 201010/510 X-Sequence-Number: 40928 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