Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1b0E5u-0002F4-KQ for pgsql-admin@arkaria.postgresql.org; Tue, 10 May 2016 20:17:26 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.84_2) (envelope-from ) id 1b0E5u-0007Ec-48 for pgsql-admin@arkaria.postgresql.org; Tue, 10 May 2016 20:17:26 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1b0E4C-0004WY-To for pgsql-admin@postgresql.org; Tue, 10 May 2016 20:15:40 +0000 Received: from out.smtp-auth.no-ip.com ([8.23.224.60]) by magus.postgresql.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.84_2) (envelope-from ) id 1b0E49-0001lt-Gw for pgsql-admin@postgresql.org; Tue, 10 May 2016 20:15:40 +0000 X-No-IP: alvh.no-ip.org@noip-smtp X-Report-Spam-To: abuse@no-ip.com Received: from alvin.alvh.no-ip.org (unknown [216.155.90.98]) (Authenticated sender: alvh.no-ip.org@noip-smtp) by smtp-auth.no-ip.com (Postfix) with ESMTPA id 9625A400EF3; Tue, 10 May 2016 13:15:30 -0700 (PDT) Received: by alvin.alvh.no-ip.org (Postfix, from userid 1000) id 1BB92181; Tue, 10 May 2016 17:15:28 -0300 (CLST) Date: Tue, 10 May 2016 17:15:28 -0300 From: Alvaro Herrera To: Tom Lane Cc: =?utf-8?B?T25kxZllaiBTdsSbdGzDrWs=?= , pgsql-admin@postgresql.org Subject: Re: Autovacuum of pg_database Message-ID: <20160510201528.GA664314@alvherre.pgsql> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4352.1462833746@sss.pgh.pa.us> User-Agent: Mutt/1.5.23 (2014-03-12) X-Pg-Spam-Score: -1.1 (-) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-admin Precedence: bulk Sender: pgsql-admin-owner@postgresql.org Tom Lane wrote: > I'll bet they're all trying to do anti-wraparound vacuums. This would > explain why the problem hasn't been observed often enough to have been > fixed long since. Ah, that should have been obvious, shouldn't it. I'm able to reproduce the problem by moving relfrozenxid backwards for a shared catalog, and I can confirm that it works correctly with the patch proposed, so I have pushed it to all branches. (I only tested the problem scenario in 9.1 and master, since it's too much manual work). Thanks for the report! -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin