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Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) - Mailing list pgsql-performance

From Mischa
Subject Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient)
Date
Msg-id 1112909198.4255a58eae0d8@webmail.telus.net
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In response to Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient)  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient)  (Tom Lane <tgl@sss.pgh.pa.us>)
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Quoting Tom Lane <tgl@sss.pgh.pa.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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