Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient)

From: Mischa <mischa(dot)Sandberg(at)telus(dot)net>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient)
Date: 2005-04-07 21:26:38
Message-ID: 1112909198.4255a58eae0d8@webmail.telus.net
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Quoting Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> Yeah, the whole thing is only a heuristic anyway. I've been coming
> around to the view that relation membership shouldn't matter, because
> of cases like
>
> WHERE a.x > b.y AND a.x < 42
>
> which surely should be taken as a range constraint.

Out of curiosity, will the planner induce "b.y < 42" out of this?

--
"Dreams come true, not free."

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