Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 04E226321E7 for ; Thu, 14 Jan 2010 17:28:22 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 78706-05 for ; Thu, 14 Jan 2010 21:28:06 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-fx0-f227.google.com (mail-fx0-f227.google.com [209.85.220.227]) by mail.postgresql.org (Postfix) with ESMTP id E524B6330E3 for ; Thu, 14 Jan 2010 17:28:10 -0400 (AST) Received: by fxm27 with SMTP id 27so1346859fxm.3 for ; Thu, 14 Jan 2010 13:28:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:received:received:received:date:from:to:cc :subject:message-id:references:mime-version:content-type :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=2QQDdxH0Nz6oP5dUNKy51Z50g92EXSNpZ+HnrrdSBpw=; b=hI43Xb4X9IxIkbY3E9VGFgFFtNM/bACeKDwnt2S3iu6YDert4wWlMsXyQyImX0MsOf XPfryI6yKDpKaEqEgB46ljav99tAcgM3GHQfpg99rhDQKelS6kNTU8+85Y/cZsKmyp0b m7kihPRE4ND/WY7WWmP9nmuVGIYpefkfoD9BM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:content-transfer-encoding :in-reply-to:user-agent; b=on8mVt8BylG1TkZkOfuSbvgQd2Iwv8BFZGoIOaRUtQ5HfdQu6htytkow9++v3IY3BW XVQfj9LTXiDwpqUxD+AaxGJf5zwUfOi6a62yae7B97Ul54Hn4MBevFA6o/FnmFk2lj5U XxV0eRQTsHPPSdPfdvPoZtJdcDh/Q02LoAmyA= Received: by 10.223.5.135 with SMTP id 7mr1732466fav.81.1263504489321; Thu, 14 Jan 2010 13:28:09 -0800 (PST) Received: from googlemail.com (port-87-193-148-114.static.qsc.de [87.193.148.114]) by mx.google.com with ESMTPS id 16sm142498fxm.0.2010.01.14.13.28.07 (version=TLSv1/SSLv3 cipher=RC4-MD5); Thu, 14 Jan 2010 13:28:08 -0800 (PST) Received: by googlemail.com (nbSMTP-1.00) for uid 1100 (using TLSv1/SSLv3 with cipher RC4-MD5 (128/128 bits)) fkater@googlemail.com; Thu, 14 Jan 2010 22:28:08 +0100 (CET) Date: Thu, 14 Jan 2010 22:28:07 +0100 From: "fkater@googlemail.com" To: Pierre =?utf-8?B?RnLDqWTDqXJpYw==?= Caillaud Cc: pgsql-performance@postgresql.org Subject: Re: Inserting 8MB bytea: just 25% of disk perf used? Message-ID: <20100114212807.GF2384@comppasch2> References: <20100114142903.GB2973@comppasch2> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.599 tagged_above=-10 required=5 tests=AWL=0.000, BAYES_00=-2.599 X-Spam-Level: X-Archive-Number: 201001/313 X-Sequence-Number: 37193 Pierre Frédéric Caillaud: > > 4 Core CPU 3 Ghz, WinXP, 1 TB SATA disk. > > Big CPU and slow disk... > > You should add another disk just for the WAL -- disks are pretty cheap > these days. > Writing the WAL on a second disk is the first thing to do on a > configuration like yours, if you are limited by writes. > It also reduces the fsync lag a lot since the disk is only doing WAL. Good idea -- where can I set the path to WAL? Felix