Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 25C229FB21D for ; Wed, 27 Sep 2006 12:36:25 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 09750-04 for ; Wed, 27 Sep 2006 15:36:21 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from lynet.oppetid.no (oppetid.no [80.65.51.2]) by postgresql.org (Postfix) with ESMTP id 148569FB1E6 for ; Wed, 27 Sep 2006 12:36:21 -0300 (ADT) Received: by lynet.oppetid.no (Postfix, from userid 1019) id EEC0611AFB4; Wed, 27 Sep 2006 17:36:19 +0200 (CEST) Date: Wed, 27 Sep 2006 17:36:19 +0200 From: Tobias Brox To: Scott Marlowe Cc: Tobias Brox , Tom Lane , pgsql-performance@postgresql.org Subject: Re: Merge Join vs Nested Loop Message-ID: <20060927153619.GG17834@oppetid.no> References: <20060926193553.GA27268@oppetid.no> <719.1159308596@sss.pgh.pa.us> <20060927094803.GA11245@oppetid.no> <1159369111.4643.0.camel@localhost.localdomain> <20060927150512.GE17834@oppetid.no> <1159370365.4643.7.camel@localhost.localdomain> <20060927152655.GF17834@oppetid.no> <1159371095.26848.84.camel@state.g2switchworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1159371095.26848.84.camel@state.g2switchworks.com> Organization: Group Nordicbet User-Agent: Mutt/1.5.9i X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.135 tagged_above=0 required=5 tests=FORGED_RCVD_HELO X-Spam-Level: X-Archive-Number: 200609/356 X-Sequence-Number: 21042 [Scott Marlowe - Wed at 10:31:35AM -0500] > And remember, you can always change any of those settings in session for > just this one query to force the planner to make the right decision. sure ... I could identify the most problematic queries, and hack up the software application to modify the config settings for those exact queries ... but it's a very ugly solution. :-) Particularly if Tom Lane is correct saying the preferance of merge join instead of nested loop is indeed a bug.