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From: Michael Glaesemann <grzm@seespotcode.net>
Subject: Re: null values in non-nullable column 
Date: Tue, 5 Dec 2006 13:05:22 +0900
To: Tom Lane <tgl@sss.pgh.pa.us>
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On Dec 5, 2006, at 12:49 , Tom Lane wrote:

> Actually I think this is a bug in the SQL spec :-(  The description of
> <joined table> says that output columns are "possibly nullable" if
> they're on the nullable side of the outer join, but it's not apparent
> that that idea is meant to negate a domain constraint.  And yet, if it
> does not, then an outer join with a NOT NULL domain column on the
> nullable side is just invalid.

Very interesting. Thanks for the explanation. I should dig into the  
spec more.

Michael Glaesemann
grzm seespotcode net