Re: postgres_fdw: oddity in costing aggregate pushdown paths - Mailing list pgsql-hackers

From Etsuro Fujita
Subject Re: postgres_fdw: oddity in costing aggregate pushdown paths
Date
Msg-id 5C010821.7050102@lab.ntt.co.jp
Whole thread Raw
In response to Re: postgres_fdw: oddity in costing aggregate pushdown paths  (Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>)
Responses Re: postgres_fdw: oddity in costing aggregate pushdown paths  (Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>)
List pgsql-hackers
(2018/11/28 13:38), Etsuro Fujita wrote:
> BTW another thing I noticed is this comment on costing aggregate
> pushdown paths using local statistics in estimate_path_cost_size:
> 
>               * Also, core does not care about costing HAVING expressions and
>               * adding that to the costs.  So similarly, here too we are not
>               * considering remote and local conditions for costing.
> 
> I think this was true when aggregate pushdown went in, but isn't anymore
> because of commit 7b6c07547190f056b0464098bb5a2247129d7aa2.  So we
> should update estimate_path_cost_size so that it accounts for the
> selectivity and cost of the HAVING expressions as well?

There seems to be no objections, I updated the patch as such.  Attached
is an updated version of the patch.

Best regards,
Etsuro Fujita

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