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 5C051180.7090804@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
(2018/11/30 18:51), Etsuro Fujita wrote:
> (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.

I revised some comments a bit and added the commit message.  Attached is
an updated patch.  If there are no objections, I'll apply this to HEAD only.

Best regards,
Etsuro Fujita

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