Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 1ED42633F1C for ; Thu, 26 Feb 2009 11:20:27 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 72596-08 for ; Thu, 26 Feb 2009 11:20:22 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail-gx0-f176.google.com (mail-gx0-f176.google.com [209.85.217.176]) by mail.postgresql.org (Postfix) with ESMTP id 854EC633A6D for ; Thu, 26 Feb 2009 11:20:13 -0400 (AST) Received: by gxk24 with SMTP id 24so1613155gxk.19 for ; Thu, 26 Feb 2009 07:20:11 -0800 (PST) MIME-Version: 1.0 Received: by 10.229.110.13 with SMTP id l13mr1026131qcp.4.1235661300696; Thu, 26 Feb 2009 07:15:00 -0800 (PST) In-Reply-To: <93739F94E0F3BA43AD72423E2482341AE064B7@sw-rz010.gsf.de> References: <93739F94E0F3BA43AD72423E2482341AE064B7@sw-rz010.gsf.de> Date: Thu, 26 Feb 2009 10:15:00 -0500 Message-ID: <16b031c0902260715k3dad5765te222578a0cdab169@mail.gmail.com> Subject: Re: Question to transaction ID wraparound From: Lee Azzarello To: pgsql-admin@postgresql.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200902/237 X-Sequence-Number: 31458 On Wed, Feb 25, 2009 at 5:05 AM, Lentes, Bernd wrote: > Hello ML, > > I'm very new to Postgres. > In the log, i got messages concerning transaction ID wraparound. > I red the documentation and made a vaccum on that database. > In the documentation i also found the hint to look in the database with > "SELECT datname, age(datfrozenxid) FROM pg_database;", which i did. > I did the command several times in a few seconds, and this number is growing very quickly, > although i'm not expecting transactions in the database. > Sometimes the number grows by 5 in one second. > I'm also astonished about the fact that all databases grow by the same amount. > Do you have any explanations for this behaviour ? > Why are the numbers growing so quickly ? What kind of work load is on the database? How frequent are UPDATE/INSERT/DELETE statements called by that workload? If you don't already have the answer to these questions, I would recommend a reporting tool like pgfouine to get them easily. -lee