X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 5C8B59DCA65 for ; Tue, 20 Dec 2005 08:32:49 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 67126-05 for ; Tue, 20 Dec 2005 08:32:51 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from mail.logix-tt.com (serval.logix-tt.com [213.239.221.42]) by postgresql.org (Postfix) with ESMTP id 94B509DC82A for ; Tue, 20 Dec 2005 08:32:46 -0400 (AST) Received: from kingfisher.intern.logix-tt.com (K8ed2.k.pppool.de [85.75.142.210]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.logix-tt.com (Postfix) with ESMTP id 1C81F24400F; Tue, 20 Dec 2005 13:39:04 +0100 (CET) Received: from [127.0.0.1] (localhost [127.0.0.1]) by kingfisher.intern.logix-tt.com (Postfix) with ESMTP id 9733FD6D09; Tue, 20 Dec 2005 13:31:55 +0100 (CET) Message-ID: <43A7F9B9.3010906@logix-tt.com> Date: Tue, 20 Dec 2005 13:31:53 +0100 From: Markus Schaber Organization: Logical Tracking and Tracing International AG, Switzerland User-Agent: Debian Thunderbird 1.0.7 (X11/20051017) X-Accept-Language: en-us, en MIME-Version: 1.0 To: PostgreSQL Performance List Subject: Re: Read only transactions - Commit or Rollback References: <16F953410A0F1346848DCB476A989CFE01D6AF@swtexchange2.technology.de> <43A7F303.8040804@logix-tt.com> <87mziwj6na.fsf@gate450.dyndns.org> In-Reply-To: <87mziwj6na.fsf@gate450.dyndns.org> X-Enigmail-Version: 0.93.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.04 required=5 tests=[AWL=0.040] X-Spam-Score: 0.04 X-Spam-Level: X-Archive-Number: 200512/486 X-Sequence-Number: 16307 Hello, Andreas, Andreas Seltenreich wrote: >>Btw, there's another setting that might make a difference: >>Having ACID-Level SERIALIZABLE or READ COMMITED? > > Well, if nonrepeatable or phantom reads would pose a problem because > of those occasional writes, you wouldn't be considering autocommit for > performance reasons either, would you? Yes, the question is purely performance-wise. We don't care about any read/write conflicts in this special case. Some time ago, I had some tests with large bulk insertions, and it turned out that SERIALIZABLE seemed to be 30% faster, which surprised us. That's why I ask this questions, and mainly because we currently cannot perform a large bunch of benchmarking. Thanks, Markus -- Markus Schaber | Logical Tracking&Tracing International AG Dipl. Inf. | Software Development GIS Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org