Re: [pgsql-hackers] Group-count estimation statistics - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [pgsql-hackers] Group-count estimation statistics
Date
Msg-id 26545.1106948988@sss.pgh.pa.us
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In response to Re: [pgsql-hackers] Group-count estimation statistics  (Josh Berkus <josh@agliodbs.com>)
Responses Re: Group-count estimation statistics  (Greg Stark <gsstark@mit.edu>)
List pgsql-hackers
Josh Berkus <josh@agliodbs.com> writes:
> Why 10?   I'd think we could come up with a slightly less arbitrary number, 

Well, it's probably within an order of magnitude of the right thing ;-).
We know we don't want 1, but 100 seems awfully optimistic.

If someone can come up with a more defensible number then I'm all for
it.  Greg Stark's thought about a power correction seemed interesting
too, though again far too optimistic to trust without some good math
to back it up.
        regards, tom lane


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