Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id D25FC9FBD5D for ; Wed, 25 Apr 2007 18:55:19 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 65516-08 for ; Wed, 25 Apr 2007 18:55:13 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 008B89FBB2C for ; Wed, 25 Apr 2007 18:55:16 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id l3PLt4P8006293; Wed, 25 Apr 2007 17:55:04 -0400 (EDT) To: Josh Berkus cc: "Zeugswetter Andreas ADI SD" , pgsql-hackers@postgresql.org, "Koichi Suzuki" , pgsql-patches@postgresql.org Subject: Re: [HACKERS] Full page writes improvement, code update In-reply-to: <200704251127.13624.josh@agliodbs.com> References: <460886E8.6040907@oss.ntt.co.jp> <200704240831.42873.josh@agliodbs.com> <200704251127.13624.josh@agliodbs.com> Comments: In-reply-to Josh Berkus message dated "Wed, 25 Apr 2007 11:27:13 -0700" Date: Wed, 25 Apr 2007 17:55:04 -0400 Message-ID: <6292.1177538104@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200704/493 X-Sequence-Number: 2060 Josh Berkus writes: > Andreas, >> So imho pg_compresslog is the correct path forward. The current >> discussion is only about whether we want a more complex pg_compresslog >> and no change to current WAL, or an increased WAL size for a less >> complex implementation. >> Both would be able to compress the WAL to the same "archive log" size. > Huh? As conceived, pg_compresslog does nothing to lower log volume for > general purposes, just on-disk storage size for archiving. It doesn't help > us at all with the tremendous amount of log we put out for an OLTP server, > for example. I don't see how what you said refutes what he said. The sticking point here is that the patch as-proposed *increases* the log volume before compression. regards, tom lane