Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 12EF29FB506 for ; Thu, 17 May 2007 11:56:00 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 94801-05 for ; Thu, 17 May 2007 11:55:49 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id AB3AE9FBA0C for ; Thu, 17 May 2007 11:55:55 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.1/8.14.1) with ESMTP id l4HEtqI9025797; Thu, 17 May 2007 10:55:52 -0400 (EDT) To: Heikki Linnakangas cc: kadams@mxlogic.com, pgsql-performance@postgresql.org Subject: Re: WAL log performance/efficiency question In-reply-to: <464C6544.9070104@enterprisedb.com> References: <1179410671.26604.3.camel@MXLRMT-208.corp.mxlogic.com> <464C6544.9070104@enterprisedb.com> Comments: In-reply-to Heikki Linnakangas message dated "Thu, 17 May 2007 15:23:00 +0100" Date: Thu, 17 May 2007 10:55:52 -0400 Message-ID: <25796.1179413752@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/300 X-Sequence-Number: 24690 Heikki Linnakangas writes: > Keaton Adams wrote: >> We are running on PostgreSQL 8.1.4 and are planning to move to 8.3 when >> it becomes available. Are there space utilization/performance >> improvements in WAL logging in the upcoming release? > One big change in 8.3 is that COPY on a table that's been created or > truncated in the same transaction doesn't need to write WAL at all, if > WAL archiving isn't enabled. There are a couple of improvements in tuple storage (the header is shorter, and short varlena fields have less overhead); those would translate pretty directly into less WAL space too. regards, tom lane