From: Karl O. Pinc <kop@meme.com>
To: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Using LIMIT 1 in plpgsql PERFORM statements
Date: Mon, 24 Oct 2005 00:25:09 +0000
Message-ID: <1130113509l.8670l.1l@mofo> (raw)
In-Reply-To: <200510231402.35612.josh@agliodbs.com>
References: <1129957521l.27845l.2l@mofo>
<200510231402.35612.josh@agliodbs.com>
On 10/23/2005 04:02:35 PM, Josh Berkus wrote:
> Karl,
>
> > PERFORM 1 FROM foo;
> > IF FOUND THEN ...
> >
> > is any slower than:
> >
> > PERFORM 1 FROM foo LIMIT 1;
> > IF FOUND THEN ...
>
> I'm wondering in what context it makes sense to call PERFORM on a
> constant.
If you want to find out if the table has any rows.
I'm really interested in what happens when
there's a WHERE qualification. I want to find
out if there's any of some particular sort of row.
But I figured it wasn't worth putting that into
the example because I didn't have anything
specific to put in the WHERE clause. I suppose
I should have put it in anyway and followed with ....
Karl <kop@meme.com>
Free Software: "You don't pay back, you pay forward."
-- Robert A. Heinlein
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To: pgsql-performance@postgresql.org
Cc: kop@meme.com, josh@agliodbs.com
Subject: Re: Using LIMIT 1 in plpgsql PERFORM statements
In-Reply-To: <1130113509l.8670l.1l@mofo>
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