Re: [HACKERS] Re: Improve OR conditions on joined columns (commonstar schema problem) - Mailing list pgsql-hackers

From Michael Paquier
Subject Re: [HACKERS] Re: Improve OR conditions on joined columns (commonstar schema problem)
Date
Msg-id 20181002011118.GT11712@paquier.xyz
Whole thread Raw
In response to Re: [HACKERS] Re: Improve OR conditions on joined columns (commonstar schema problem)  (Noah Misch <noah@leadboat.com>)
Responses Re: [HACKERS] Re: Improve OR conditions on joined columns (common star schema problem)
List pgsql-hackers
On Mon, Sep 03, 2018 at 06:59:10PM -0700, Noah Misch wrote:
> If you're going to keep this highly-simplified estimate, please expand the
> comment to say why it doesn't matter or what makes it hard to do better.  The
> non-planunionor.c path for the same query computes its own estimate of the
> same underlying quantity.  Though it may be too difficult in today's system,
> one could copy the competing path's row count estimate here.  Perhaps it
> doesn't matter because higher-level processing already assumes equal row count
> among competitors?

As there has been no replies to Noah's review for one month, I am
marking this patch as returned with feedback for now.
--
Michael

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