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To: Randall Lucas <rlucas@tercent.net>
Cc: Michael Teter <michael_teter@yahoo.com>, pgsql-sql@postgresql.org
Subject: Re: UNIQUE boolean: only one row may be "true" 
In-reply-to: <19ACA479-7FF3-11D7-A71E-000A957653D6@tercent.net> 
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Comments: In-reply-to Randall Lucas <rlucas@tercent.net>
	message dated "Tue, 06 May 2003 14:46:51 -0400"
Date: Tue, 06 May 2003 23:00:51 -0400
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From: Tom Lane <tgl@sss.pgh.pa.us>
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Randall Lucas <rlucas@tercent.net> writes:
> Do you have any suggestions on how this might 
> better be implemented?  It seems to me that with a partial index, there 
> is not too much overhead and it doesn't seem too offensively 
> un-boycecoddean.

FWIW, I'd go with the unique partial index too.  It's a very efficient
solution.  But it's not portable :-(.  I'd be interested to hear what
people would do to solve this problem in bog-standard SQL.

			regards, tom lane