Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id C1CFB6380CA for ; Thu, 14 Jan 2010 10:49:50 -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 75221-05 for ; Thu, 14 Jan 2010 14:49:31 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by mail.postgresql.org (Postfix) with ESMTP id 14CBB637426 for ; Thu, 14 Jan 2010 10:49:40 -0400 (AST) Received: from list by lo.gmane.org with local (Exim 4.50) id 1NVR0y-00019C-IQ for pgsql-performance@postgresql.org; Thu, 14 Jan 2010 15:49:36 +0100 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 14 Jan 2010 15:49:36 +0100 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 14 Jan 2010 15:49:36 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: pgsql-performance@postgresql.org From: Ivan Voras Subject: Re: Inserting 8MB bytea: just 25% of disk perf used? Date: Thu, 14 Jan 2010 15:49:16 +0100 Lines: 18 Message-ID: References: <20100114142903.GB2973@comppasch2> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Thunderbird 2.0.0.23 (X11/20091210) In-Reply-To: <20100114142903.GB2973@comppasch2> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.594 tagged_above=-10 required=5 tests=AWL=0.005, BAYES_00=-2.599 X-Spam-Level: X-Archive-Number: 201001/274 X-Sequence-Number: 37154 fkater@googlemail.com wrote: > Hello together, > > I need to increase the write performance when inserting > bytea of 8MB. I am using 8.2.4 on windows with libpq. > > This takes about 50s, so, 800MB/50s = 16MB/s. > > However the harddisk (sata) could write 43 MB/s in the worst > case! Why is write performance limited to 16 MB/s? > > > Do you have any further idea why 16MB/s seems to be the > limit here? Are you doing it locally or over a network? If you are accessing the server over a network then it could be the location of the bottleneck.