Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id C6BC6133740B for ; Sun, 16 Jan 2011 13:32:53 -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 24399-02 for ; Sun, 16 Jan 2011 17:32:46 +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 5684B13364DE for ; Sun, 16 Jan 2011 13:32:46 -0400 (AST) 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 p0GHWUlH009304; Sun, 16 Jan 2011 12:32:30 -0500 (EST) To: Josh Berkus cc: Greg Smith , Robert Haas , Magnus Hagander , pgsql-hackers@postgresql.org Subject: Re: auto-sizing wal_buffers In-reply-to: <4D3220E3.20804@agliodbs.com> References: <20767.1294964709@sss.pgh.pa.us> <4D314406.3000703@2ndquadrant.com> <4D3220E3.20804@agliodbs.com> Comments: In-reply-to Josh Berkus message dated "Sat, 15 Jan 2011 14:34:11 -0800" Date: Sun, 16 Jan 2011 12:32:30 -0500 Message-ID: <9303.1295199150@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.91 tagged_above=-5 required=5 tests=BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201101/1344 X-Sequence-Number: 179181 Josh Berkus writes: > I think we can be more specific on that last sentence; is there even any > *theoretical* benefit to settings above 16MB, the size of a WAL segment? IIRC there's a forced fsync at WAL segment switch, so no. regards, tom lane