From: Jean-Luc Lachance <jllachan@nsd.ca>
To: Josh Berkus <josh@agliodbs.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-sql@postgresql.org
Subject: Re: BOOLEAN question
Date: Wed, 30 Oct 2002 11:26:11 -0500
Message-ID: <3DC00823.7396E79C@nsd.ca> (raw)
References: <web-1804001@davinci.ethosmedia.com>
Why not simply:
SELECT COALESCE( (SELECT true FROM ... WHERE boolcol LIMIT 1), FALSE);
JLL
Josh Berkus wrote:
>
> Tom,
>
> > Perhaps
> > SELECT true = ANY (SELECT boolcol FROM ...);
> > or
> > SELECT true IN (SELECT boolcol FROM ...);
> >
> > Which is not to say that MAX(bool) might not be a nicer solution;
> > but you can definitely do it with SQL-spec constructs.
>
> Based on some rough testing,
>
> SELECT true = ANY ( SELECT boolcol FROM complex query )
>
> Is marginlly faster than
>
> SELECT max(boolcol) FROM complex query
>
> With a custom MAX(boolean) function.
>
> So I'll stick to ANY().
>
> -Josh
>
> ______AGLIO DATABASE SOLUTIONS___________________________
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To: pgsql-sql@postgresql.org
Cc: jllachan@nsd.ca, josh@agliodbs.com, tgl@sss.pgh.pa.us
Subject: Re: BOOLEAN question
In-Reply-To: <3DC00823.7396E79C@nsd.ca>
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