Rearranging simple where clauses - Mailing list pgsql-general

From Michael Graham
Subject Rearranging simple where clauses
Date
Msg-id 1304516689.24106.40.camel@brutus
Whole thread Raw
Responses Re: Rearranging simple where clauses  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
Hi,

I was playing around with some sql in postgres and got to wondering why
the optimiser can't figure out that rearranging some expressions can
result in massive improvements in the queue plan.  For example id + 5 <
100 compared with id < 100 - 5.

Is it simply that no one has go around to doing it or is there some
deeper reasons?  It's not really important I'm just curious.

Cheers,
--
Michael Graham <mgraham@bloxx.com>



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