Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 698922E0037 for ; Mon, 24 Mar 2008 04:41:55 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 18684-05 for ; Mon, 24 Mar 2008 04:41:51 -0300 (ADT) X-Greylist: delayed 00:20:12.597804 by SQLgrey-1.7.5 Received: from proxy1.bredband.net (proxy1.bredband.net [195.54.101.71]) by postgresql.org (Postfix) with ESMTP id 4A1F62E002C for ; Mon, 24 Mar 2008 04:41:51 -0300 (ADT) Received: from ironport2.bredband.com (195.54.101.122) by proxy1.bredband.net (7.3.127) id 47E10B8B001292D3 for pgsql-performance@postgresql.org; Mon, 24 Mar 2008 08:21:35 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Aj1JALPz5kdT48yuPGdsb2JhbACBW48yAQEBATCUeQ Received: from ua-83-227-204-174.cust.bredbandsbolaget.se (HELO mail.zigo.dhs.org) ([83.227.204.174]) by ironport2.bredband.com with ESMTP; 24 Mar 2008 08:21:35 +0100 Received: from cosmo.zigo.dhs.org (cosmo.zigo.dhs.org [192.168.0.3]) by mail.zigo.dhs.org (Postfix) with ESMTP id CACB048087 for ; Mon, 24 Mar 2008 08:09:13 +0100 (CET) Message-ID: <47E7567C.1090804@zigo.dhs.org> Date: Mon, 24 Mar 2008 08:21:32 +0100 From: Dennis Bjorklund User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: PostgreSQL Performance Subject: Turn correlated in subquery into join Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200803/436 X-Sequence-Number: 29390 Look like the mysql people found a subquery that postgresql doesn't handle as good as possible: http://s.petrunia.net/blog/ Is there some deeper issue here that I fail to see or is it simply that it hasn't been implemented but is fairly straigt forward? In the link above they do state that it isn't a very common case anyway. /Dennis