Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id C4BFC13364DE for ; Fri, 7 Jan 2011 09:45:10 -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 97476-08 for ; Fri, 7 Jan 2011 13:45:03 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mx01.bfk.de (mx01.bfk.de [193.227.124.2]) by mail.postgresql.org (Postfix) with ESMTP id 22B921337B8A for ; Fri, 7 Jan 2011 09:45:02 -0400 (AST) Received: from mx00.int.bfk.de ([10.119.110.2]) by mx01.bfk.de with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) id 1PbCco-0002mv-7Q; Fri, 07 Jan 2011 13:45:02 +0000 Received: by bfk.de with local id 1PbCco-0003h4-3x; Fri, 07 Jan 2011 13:45:02 +0000 To: Andres Freund Cc: pgsql-performance@postgresql.org Subject: Re: Wrong docs on checkpoint_segments? References: <82aajcg9wa.fsf@mid.bfk.de> <201101071439.32053.andres@anarazel.de> From: Florian Weimer Date: Fri, 07 Jan 2011 13:45:02 +0000 In-Reply-To: <201101071439.32053.andres@anarazel.de> (Andres Freund's message of "Fri\, 7 Jan 2011 14\:39\:31 +0100") Message-ID: <82mxnceskh.fsf@mid.bfk.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable 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: 201101/43 X-Sequence-Number: 41830 * Andres Freund: > On Friday, January 07, 2011 01:45:25 PM Florian Weimer wrote: >> On 9.0, this configuration >>=20 >> checkpoint_segments =3D 512 # in logfile segments, min 1, 16MB each >>=20 >> results in 1034 segments, so the effective logfile segment size is 32 MB. > Um. Is it possible that you redefined XLOG_SEG_SIZE or used --with-wal- > segsize=3DSEGSIZE? No, the individual files are still 16 MB. It's just that the checkpoint_segments limit is not a hard limit, and you end up with slightly more than twice the configured number of segments on disk. --=20 Florian Weimer BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstra=DFe 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99