Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 0109663392C for ; Thu, 14 Jan 2010 11:15:01 -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 80520-06 for ; Thu, 14 Jan 2010 15:14:41 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mx01.bfk.de (mx01.bfk.de [193.227.124.2]) by mail.postgresql.org (Postfix) with ESMTP id 3605963369B for ; Thu, 14 Jan 2010 11:14:50 -0400 (AST) Received: from mx00.int.bfk.de ([10.119.110.2]) by mx01.bfk.de with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) id 1NVRPJ-0000Qa-JW; Thu, 14 Jan 2010 15:14:45 +0000 Received: by bfk.de with local id 1NVRPK-0003cC-W1; Thu, 14 Jan 2010 15:14:46 +0000 To: "fkater\@googlemail.com" Cc: pgsql-performance@postgresql.org Subject: Re: Inserting 8MB bytea: just 25% of disk perf used? References: <20100114142903.GB2973@comppasch2> From: Florian Weimer Date: Thu, 14 Jan 2010 15:14:46 +0000 In-Reply-To: <20100114142903.GB2973@comppasch2> (fkater@googlemail.com's message of "Thu\, 14 Jan 2010 15\:29\:03 +0100") Message-ID: <82aawgoh09.fsf@mid.bfk.de> MIME-Version: 1.0 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=-1.67 tagged_above=-10 required=5 tests=AWL=-0.930, BAYES_20=-0.74 X-Spam-Level: X-Archive-Number: 201001/279 X-Sequence-Number: 37159 > Do you have any further idea why 16MB/s seems to be the limit here? BYTEA deserialization is very slow, and this could be a factor here. Have you checked that you are in fact I/O bound? You can speed things up by sending the data in binary, by passing approriate parameters to PQexecParams(). --=20 Florian Weimer BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstra=DFe 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99