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Re: Does optimizer know about 'constant' expressions? - Mailing list pgsql-sql

From Tom Lane
Subject Re: Does optimizer know about 'constant' expressions?
Date
Msg-id 6821.969214583@sss.pgh.pa.us
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In response to Does optimizer know about 'constant' expressions?  (Philip Warner <pjw@rhyme.com.au>)
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Philip Warner <pjw@rhyme.com.au> writes:
> It seems that the optimizer does not know about (or calculate values of)
> constant expressions when determining strategy.

Datetime calculations are not considered constant-foldable.  See
prior discussions, eg thread "Constant propagation and similar issues"
in pghackers on 11-Sep.
        regards, tom lane

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