X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id B01EC11F64E0 for ; Thu, 27 Apr 2006 06:26:28 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 12986-08 for ; Thu, 27 Apr 2006 06:26:19 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey- Received: from nz-out-0102.google.com (nz-out-0102.google.com [64.233.162.201]) by postgresql.org (Postfix) with ESMTP id 4720A11F60E5 for ; Thu, 27 Apr 2006 06:26:18 -0300 (ADT) Received: by nz-out-0102.google.com with SMTP id 9so1523586nzo for ; Thu, 27 Apr 2006 02:26:18 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=bQPHjeyQ/9eS+l3CO+BigvIQBm1DF7pp3a/6CvowNCiQcAu079+r2AxqB8n6bXEWPZoh/wq+Zj9cbp3rbW2v7RN4diPB2OLVxrxnNjEJcyLyfL8YSmsZzQ+AmIdVuapM1oXplc+jpukQ9KDPt+icV8kNFHCe0T9pFvxap9rkpTI= Received: by 10.65.116.2 with SMTP id t2mr528049qbm; Thu, 27 Apr 2006 02:26:18 -0700 (PDT) Received: by 10.65.122.19 with HTTP; Thu, 27 Apr 2006 02:26:18 -0700 (PDT) Message-ID: <1d4e0c10604270226s53e261e9m943bf44766c880bf@mail.gmail.com> Date: Thu, 27 Apr 2006 11:26:18 +0200 From: "Guillaume Smet" To: guoping.zhang@nec.com.au Subject: Re: how unsafe (or worst scenarios) when setting fsync OFF for postgresql Cc: pgsql-performance@postgresql.org, "Guoping Zhang (E-mail)" In-Reply-To: <003b01c669c4$34bbd7b0$74304c93@eddy> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <003b01c669c4$34bbd7b0$74304c93@eddy> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200604/630 X-Sequence-Number: 18714 Guoping, On 4/27/06, Guoping Zhang wrote: > We have to looking at setting fsync OFF option for performance reason, Did you try the other wal sync methods (fdatasync in particular)? I saw a few posts lately explaining how changing sync method can affect performances in specific cases. -- Guillaume