Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 858C71337B4A for ; Sun, 26 Dec 2010 00:30:40 -0400 (AST) 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 99108-06 for ; Sun, 26 Dec 2010 04:30:33 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from hrndva-omtalb.mail.rr.com (hrndva-omtalb.mail.rr.com [71.74.56.123]) by mail.postgresql.org (Postfix) with ESMTP id 32C611337B39 for ; Sun, 26 Dec 2010 00:30:33 -0400 (AST) X-Authority-Analysis: v=1.1 cv=UQuFHoD2CPQ248x8AXEbKhr4z9AaDqApxmEl3BhfZ64= c=1 sm=0 a=L7WWzgpysToA:10 a=JRZeEW2aRuwA:10 a=8nJEP1OIZ-IA:10 a=RAii6je2cdnAH6ATCOpc6g==:17 a=_Ixf_7qHAAAA:8 a=VGLH-1YGJoDn12EpNI4A:9 a=SsJ93D1qbFh_IQ6uiVRgF67KuJ4A:4 a=wPNLvfGTeEIA:10 a=ryAo9hy1-OkA:10 a=6vsjEBoLwlAA:10 a=0tfO7MgyNwYA:10 a=RAii6je2cdnAH6ATCOpc6g==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.73.87.196 Received: from [74.73.87.196] ([74.73.87.196:14326] helo=[192.168.1.100]) by hrndva-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id E8/90-00963-8E4C61D4; Sun, 26 Dec 2010 04:30:32 +0000 Message-ID: <4D16C4E8.2000404@vmsinfo.com> Date: Sat, 25 Dec 2010 23:30:32 -0500 From: Mladen Gogala Reply-To: mladen.gogala@vmsinfo.com Organization: VMS User-Agent: Thunderbird 2.0.0.24 (X11/20101213) MIME-Version: 1.0 To: Jeff Janes CC: "wozniak@lanl.gov" , Scott Marlowe , "pgsql-performance@postgresql.org" Subject: Re: concurrent IO in postgres? References: <1293125873.3685.91.camel@procyon.lanl.gov> <1293133617.3685.97.camel@procyon.lanl.gov> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.9 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001 X-Spam-Level: X-Archive-Number: 201012/308 X-Sequence-Number: 41760 Jeff Janes wrote: > If the background writer cannot keep up, then the individual backends > start doing writes as well, so it isn't really serialized.. > > Is there any parameter governing that behavior? Can you tell me where in the code (version 9.0.2) can I find that? Thanks. -- Mladen Gogala Sr. Oracle DBA 1500 Broadway New York, NY 10036 (212) 329-5251 www.vmsinfo.com