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 763469DC81A for ; Tue, 20 Dec 2005 08:04:09 -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 60071-07 for ; Tue, 20 Dec 2005 08:04:10 -0400 (AST) X-Greylist: delayed 01:22:20.244344 by SQLgrey- Received: from mail.logix-tt.com (serval.logix-tt.com [213.239.221.42]) by postgresql.org (Postfix) with ESMTP id 20C179DC82A for ; Tue, 20 Dec 2005 08:04:06 -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 6F55324400F for ; Tue, 20 Dec 2005 13:10:23 +0100 (CET) Received: from [127.0.0.1] (localhost [127.0.0.1]) by kingfisher.intern.logix-tt.com (Postfix) with ESMTP id 4F8DED6D0D for ; Tue, 20 Dec 2005 13:03:16 +0100 (CET) Message-ID: <43A7F303.8040804@logix-tt.com> Date: Tue, 20 Dec 2005 13:03:15 +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> In-Reply-To: <16F953410A0F1346848DCB476A989CFE01D6AF@swtexchange2.technology.de> X-Enigmail-Version: 0.93.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0 required=5 tests=[none] X-Spam-Score: 0 X-Spam-Level: X-Archive-Number: 200512/483 X-Sequence-Number: 16304 Hi, Marcus, Nörder-Tuitje wrote: > afaik, this should be completely neglectable. > > starting a transaction implies write access. if there is none, You do > not need to think about transactions, because there are none. Hmm, I always thought that the transaction will be opened at the first statement, because there _could_ be a parallel writing transaction started later. > postgres needs to schedule the writing transactions with the reading > ones, anyway. As I said, there usually are no writing transactions on the same database. Btw, there's another setting that might make a difference: Having ACID-Level SERIALIZABLE or READ COMMITED? 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