Received: from localhost (maia-4.hub.org [200.46.204.183])
	by postgresql.org (Postfix) with ESMTP id 356479FB667
	for <pgsql-performance-postgresql.org@postgresql.org>;
	Mon, 16 Apr 2007 20:55:11 -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 70384-06 for
	<pgsql-performance-postgresql.org@postgresql.org>;
	Mon, 16 Apr 2007 20:55:08 -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 B4BE59FB5D2
	for <pgsql-performance@postgresql.org>;
	Mon, 16 Apr 2007 20:55:08 -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 l3GNt6WO012252;
	Mon, 16 Apr 2007 19:55:06 -0400 (EDT)
To: cluster <skrald@amossen.dk>
cc: pgsql-performance@postgresql.org
Subject: Re: FK triggers misused? 
In-reply-to: <f00vq0$2ncr$1@news.hub.org> 
References: <evqm6g$29b1$1@news.hub.org> <26399.1176614941@sss.pgh.pa.us>
	<slrnf23eqp.10cj.andrew+nonews@atlantis.supernews.net>
	<102.1176650563@sss.pgh.pa.us>
	<slrnf258g3.10cj.andrew+nonews@atlantis.supernews.net>
	<f00vq0$2ncr$1@news.hub.org>
Comments: In-reply-to cluster <skrald@amossen.dk>
	message dated "Tue, 17 Apr 2007 01:12:28 +0200"
Date: Mon, 16 Apr 2007 19:55:06 -0400
Message-ID: <12251.1176767706@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200704/321
X-Sequence-Number: 24198

Idly thumbing through the code, I came across something that might
possibly explain your results.  Do the rows being updated contain
NULLs in the foreign-key columns?  I see that ri_KeysEqual() treats
two null values as not equal, which might be overzealous respect for
SQL null semantics in this context.

			regards, tom lane