Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id 023621337B49 for ; Thu, 16 Dec 2010 08:14:47 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 46344-04 for ; Thu, 16 Dec 2010 12:14:39 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from ibook.office.archonet.com (84-51-143-99.archon037.adsl.metronet.co.uk [84.51.143.99]) by mail.postgresql.org (Postfix) with ESMTP id 9C7CC1337B53 for ; Thu, 16 Dec 2010 08:14:39 -0400 (AST) Received: from [192.168.1.36] (dell36.office.archonet.com [192.168.1.36]) by ibook.office.archonet.com (Postfix) with ESMTP id A3C027C121; Thu, 16 Dec 2010 12:14:37 +0000 (GMT) Message-ID: <4D0A02A8.5050206@archonet.com> Date: Thu, 16 Dec 2010 12:14:32 +0000 From: Richard Huxton User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.13) Gecko/20101208 Lightning/1.0b2 Thunderbird/3.1.7 MIME-Version: 1.0 To: Werner Scholtes CC: Divakar Singh , "pgsql-performance@postgresql.org" Subject: Re: performance libpq vs JDBC References: <128DB53227227D43B4AAEED73E89A81901E2C4B584@vm-exchg-2k8.heuboe.hbintern> <209185.49892.qm@web65409.mail.ac4.yahoo.com> <128DB53227227D43B4AAEED73E89A81901E2C4B58B@vm-exchg-2k8.heuboe.hbintern> In-Reply-To: <128DB53227227D43B4AAEED73E89A81901E2C4B58B@vm-exchg-2k8.heuboe.hbintern> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-0.918 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RDNS_DYNAMIC=0.982 X-Spam-Level: X-Archive-Number: 201012/189 X-Sequence-Number: 41641 On 16/12/10 09:21, Werner Scholtes wrote: > I assume that the wire protocol of PostgreSQL allows to transmit > multiple rows at once, but libpq doesn't have an interface to access it. > Is that right? Sounds wrong to me. The libpq client is the default reference implementation of the protocol. If there were large efficiencies that could be copied, they would be. Anyway - you don't need to assume what's in the protocol. It's documented here: http://www.postgresql.org/docs/9.0/static/protocol.html I'd stick wireshark or some other network analyser on the two sessions - see exactly what is different. -- Richard Huxton Archonet Ltd