X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org
Received: from localhost (av.hub.org [200.46.204.144])
	by svr1.postgresql.org (Postfix) with ESMTP id E4DF9D8B7F
	for <pgsql-sql-postgresql.org@localhost.postgresql.org>;
	Tue, 13 Sep 2005 01:59:13 -0300 (ADT)
Received: from svr1.postgresql.org ([200.46.204.71])
	by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024)
	with ESMTP id 40445-05
	for <pgsql-sql-postgresql.org@localhost.postgresql.org>;
	Tue, 13 Sep 2005 04:58:57 +0000 (GMT)
Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130])
	by svr1.postgresql.org (Postfix) with ESMTP id BF1F5D8D11
	for <pgsql-sql@postgresql.org>; Tue, 13 Sep 2005 01:58:57 -0300 (ADT)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
	by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id j8D4wt80019186;
	Tue, 13 Sep 2005 00:58:55 -0400 (EDT)
To: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>
Cc: pgsql-sql@postgresql.org
Subject: Re: user defined type, plpgsql function and NULL 
In-reply-to: <dforj9$9cg$1@news.germany.com> 
References: <dforj9$9cg$1@news.germany.com>
Comments: In-reply-to "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>
	message dated "Thu, 08 Sep 2005 08:09:13 -0000"
Date: Tue, 13 Sep 2005 00:58:55 -0400
Message-ID: <19185.1126587535@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
X-Virus-Scanned: by amavisd-new at hub.org
X-Spam-Status: No, hits=0.006 required=5 tests=[AWL=0.006]
X-Spam-Level: 
X-Archive-Number: 200509/142
X-Sequence-Number: 22689

"Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net> writes:
> Is this correct or is it just a "works like that this time but may
> change at any time in the future"?

The meaning of a NULL for a composite value isn't real well-defined
at the moment.  I tend to agree that "fbt IS NULL" should yield true
in your example, but I think there are/were some implementation reasons
why it doesn't.

			regards, tom lane