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Re: Proposal - improve eqsel estimates by including histogram bucket numdistinct statistics - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Proposal - improve eqsel estimates by including histogram bucket numdistinct statistics
Date
Msg-id 12033.1213294051@sss.pgh.pa.us
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In response to Re: Proposal - improve eqsel estimates by including histogram bucket numdistinct statistics  ("Nathan Boley" <npboley@gmail.com>)
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"Nathan Boley" <npboley@gmail.com> writes:
> Given that, wouldn't it be smarter to consider a value as an mcv
> candidate iff it has a density greater than 0.005, rather than having
> a count greater than 1.5*average?

Yeah, perhaps ... want to experiment with that?  Though I'd be a bit
worried about how to get the threshold right, seeing that it will
depend a whole lot on what the user has selected for random_page_cost
and other parameters.
        regards, tom lane

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