Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 88A4A6332D3 for ; Wed, 25 Feb 2009 13:42:37 -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 04161-06 for ; Wed, 25 Feb 2009 13:42:32 -0400 (AST) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from yw-out-2324.google.com (yw-out-2324.google.com [74.125.46.29]) by mail.postgresql.org (Postfix) with ESMTP id 74FFB6332CF for ; Wed, 25 Feb 2009 13:42:32 -0400 (AST) Received: by yw-out-2324.google.com with SMTP id 5so87709ywh.73 for ; Wed, 25 Feb 2009 09:42:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=dC5/ifB0Rbx/1ysQmthfxkDV6qiRpLZW61LzUspdt+g=; b=mKSCTgLtkm1RVTeCp8Mh/tn0Atw9N/GHTGg1s7TgzD4t3unBu8UUoXs0gx5f3WAPht zTJGIPKR/JGFNLa0j7r3HUK5lfrVxNhvEPpa4xfpZV64t8lz7t0P3xzPQa3KK70pHWeQ 2i31IhoRqTkmVcsy6ZKex4QVg5mxLn9m5qlBk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=tr+Q3scd4oAfP8zB6T/Yg2+M3yEQkqSF1Q1rZOaDqXrxpGxsksU0aJ8x7eJAXj3UKX t1I5jb9StZIW5fXMLsNzPYHJtsGZ1VO3z2xrF2ZmlNMsraPxUWQ2EIe934FyJWp/n44V /NcY5glQoV7rE7zSQ8JsfaaXhyMG65oRTS1R0= MIME-Version: 1.0 Received: by 10.143.42.7 with SMTP id u7mr157491wfj.99.1235583751299; Wed, 25 Feb 2009 09:42:31 -0800 (PST) In-Reply-To: <3161.1234541940@sss.pgh.pa.us> References: <507152DDF8AB4DF093BD01A8BEC7C659@squarepi.com> <25753.1234224090@sss.pgh.pa.us> <4991338B.704@kickstone.com> <4994906B.6090408@kickstone.com> <17204.1234474784@sss.pgh.pa.us> <4994987F.1030204@kickstone.com> <17764.1234476783@sss.pgh.pa.us> <4994A45B.4030707@kickstone.com> <49952D33.3000707@kickstone.com> <3161.1234541940@sss.pgh.pa.us> Date: Wed, 25 Feb 2009 23:12:31 +0530 Message-ID: <2e78013d0902250942u7d6103fev96e3b6d4eb20e5b8@mail.gmail.com> Subject: Re: Database corruption help From: Pavan Deolasee To: Tom Lane Cc: John Lister , pgsql-hackers@postgresql.org 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=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200902/1224 X-Sequence-Number: 134514 On Fri, Feb 13, 2009 at 9:49 PM, Tom Lane wrote: > > The only other corruption mechanism I can think of is that pg_clog might > contain commit bits for some logically inconsistent set of transaction > numbers, due to some pages of pg_clog having made it to disk and others > not. =A0That could result in some of the intermediate tuples in the chain > not being seen as dead --- but that's not what we see here either. > Or can it be otherwise where some transactions which in fact committed, are marked as aborted because of clog corruption ? In that case, some of the intermediate tuples in the HOT chain may get removed (because we handle aborted heap-only tuples separately) and break the HOT chain. I am also looking at the pruning logic to see if I can spot something unusu= al. Thanks, Pavan --=20 Pavan Deolasee EnterpriseDB http://www.enterprisedb.com