Received: from localhost (unknown [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 30CD12E00DC for ; Sat, 1 Dec 2007 04:02:38 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 21938-07 for ; Sat, 1 Dec 2007 04:02:32 -0400 (AST) Received: from mx27.mail.ru (mx27.mail.ru [194.67.23.23]) by postgresql.org (Postfix) with ESMTP id 95DAA2E3844 for ; Sat, 1 Dec 2007 04:02:32 -0400 (AST) Received: from [217.25.23.15] (port=19283 helo=[217.25.23.15]) by mx27.mail.ru with esmtp id 1IyNJ0-000ELC-00 for pgsql-general@postgresql.org; Sat, 01 Dec 2007 11:02:31 +0300 Message-ID: <4751150F.8080604@mail.ru> Date: Sat, 01 Dec 2007 12:02:23 +0400 From: rihad User-Agent: Icedove 1.5.0.14pre (X11/20071018) MIME-Version: 1.0 To: pgsql-general@postgresql.org Subject: full_page_writes = off? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200712/2 X-Sequence-Number: 124747 Hi, would full_page_writes=off increase the risk of inconsistency or db corruption in 8.3 and FreeBSD 7? fsync = on; Definitely "on", as single power outage after three years is guaranteed to make your life interesting otherwise. synchronous_commit = off; Can be "off" in my case as I'm not doing any "external" actions based on transaction's success or failure (if I understand the docs correctly). So I don't care at which moment the evil strikes as long as the db is consistent. full_page_writes = off; AFAIK when this is "on" it means synchronous WAL writing with less impact, as it occurs once per checkpoint, but it's still synchronous. Not sure at all about this one. How would FreeBSD 7's UFS survive the power crash etc. with this set to "off"? OTOH, does "on" play well with synchronous_commit=off? Meaning, will the transaction holder get success immediately on commit, still guaranteeing consistency? Thanks for any insights or clarifying missed points.