X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id DAAB65285A for ; Thu, 28 Jul 2005 15:19:37 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 20061-05 for ; Thu, 28 Jul 2005 18:19:29 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id AEA0052A01 for ; Thu, 28 Jul 2005 15:19:28 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id j6SIJS06025775; Thu, 28 Jul 2005 14:19:29 -0400 (EDT) To: Steven Rosenstein Cc: pgsql-performance@postgresql.org Subject: Re: Unable to explain DB error In-reply-to: References: Comments: In-reply-to Steven Rosenstein message dated "Thu, 28 Jul 2005 13:00:05 -0400" Date: Thu, 28 Jul 2005 14:19:28 -0400 Message-ID: <25774.1122574768@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.006 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200507/444 X-Sequence-Number: 13685 Steven Rosenstein writes: > Any idea why Postgres would be looking for a clog file name 0FC0 when the most recent filename is 04CE? Corrupt data --- specifically a bad transaction number in a tuple header. (In practice, this is the first field looked at in which we can readily detect an error, so you tend to see this symptom for any serious data corruption situation. The actual fault may well be something like a corrupt page header causing the code to follow "tuple pointers" that point to garbage.) See the PG list archives for past discussions of dealing with corrupt data. pgsql-performance is pretty off-topic for this. BTW, PG 7.4 and up handle this sort of thing much more gracefully ... they can't resurrect corrupt data of course, but they tend not to panic. regards, tom lane