Re: BOOLEAN question

From: Jean-Luc Lachance <jllachan(at)nsd(dot)ca>
To: Josh Berkus <josh(at)agliodbs(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-sql(at)postgresql(dot)org
Subject: Re: BOOLEAN question
Date: 2002-10-30 16:26:11
Message-ID: 3DC00823.7396E79C@nsd.ca
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-sql

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___________________________
> Josh Berkus
> Complete information technology josh(at)agliodbs(dot)com
> and data management solutions (415) 565-7293
> for law firms, small businesses fax 621-2533
> and non-profit organizations. San Francisco
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo(at)postgresql(dot)org

In response to

Responses

Browse pgsql-sql by date

  From Date Subject
Next Message Jean-Luc Lachance 2002-10-30 16:38:18 Re: BOOLEAN question
Previous Message Dan Hrabarchuk 2002-10-30 15:30:56 Re: [SQL] Database Design tool