Re: Improving N-Distinct estimation by ANALYZE - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Improving N-Distinct estimation by ANALYZE
Date
Msg-id 17803.1137443903@sss.pgh.pa.us
Whole thread Raw
In response to Re: Improving N-Distinct estimation by ANALYZE  (Simon Riggs <simon@2ndquadrant.com>)
List pgsql-hackers
Simon Riggs <simon@2ndquadrant.com> writes:
> Tom has not spoken against checking for UNIQUE constraints: he is just
> pointing out that there never could be a constraint in the case I was
> identifying.

More generally, arguing for or against any system-wide change on the
basis of performance of compute_minimal_stats() is folly, because that
function is not used for any common datatypes.  (Ideally it'd never be
used at all.)
        regards, tom lane


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