Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id 6935C1337B90 for ; Tue, 16 Nov 2010 21:18:08 -0400 (AST) 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 04107-01-3 for ; Wed, 17 Nov 2010 01:18:00 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from glacier.frostconsultingllc.com (glacier.frostconsultingllc.com [69.36.227.170]) by mail.postgresql.org (Postfix) with ESMTP id 38C001337BD1 for ; Tue, 16 Nov 2010 21:17:46 -0400 (AST) Received: from dsl081-245-111.sfo1.dsl.speakeasy.net ([64.81.245.111] helo=Sidney-Stratton.local) by glacier.frostconsultingllc.com with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.69) (envelope-from ) id 1PIWec-00088N-Sw; Tue, 16 Nov 2010 17:17:45 -0800 Message-ID: <4CE32D36.5040902@agliodbs.com> Date: Tue, 16 Nov 2010 17:17:42 -0800 From: Josh Berkus User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20090223 Thunderbird/3.0b2 MIME-Version: 1.0 To: Tom Lane CC: pgsql-performance@postgresql.org, Greg Smith Subject: Re: Defaulting wal_sync_method to fdatasync on Linux for 9.1? References: <4CCDCAA3.4050805@2ndquadrant.com> <201011010010.28724.andres@anarazel.de> <4CD472CC.80006@2ndquadrant.com> <4CE2EBF8.4040602@2ndquadrant.com> <4CE312D9.6030503@agliodbs.com> <9058.1289950294@sss.pgh.pa.us> In-Reply-To: <9058.1289950294@sss.pgh.pa.us> Content-Type: text/plain; charset=UTF-8 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 X-Spam-Level: X-Archive-Number: 201011/278 X-Sequence-Number: 41302 > Well, we're not going to increase the default to gigabytes, but we could > very probably increase it by a factor of 10 or so without anyone > squawking. It's been awhile since I heard of anyone trying to run PG in > 4MB shmmax. How much would a change of that size help? Last I checked, though, this comes out of the allocation available to shared_buffers. And there definitely are several OSes (several linuxes, OSX) still limited to 32MB by default. -- -- Josh Berkus PostgreSQL Experts Inc. http://www.pgexperts.com