From: Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>
To: Pg Hackers <pgsql-hackers@postgresql.org>
Subject: Re: postgres_fdw: oddity in costing aggregate pushdown paths
Date: Tue, 04 Dec 2018 17:24:23 +0900
Message-ID: <5C0639B7.1080006@lab.ntt.co.jp> (raw)
In-Reply-To: <5C051180.7090804@lab.ntt.co.jp>
References: <5BFD3EAD.2060301@lab.ntt.co.jp>
<5BFE1BDE.7010306@lab.ntt.co.jp>
<5C010821.7050102@lab.ntt.co.jp>
<5C051180.7090804@lab.ntt.co.jp>
(2018/12/03 20:20), Etsuro Fujita wrote:
> (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.
Done after fixing typos in the commit message.
Best regards,
Etsuro Fujita
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To: pgsql-hackers@postgresql.org
Cc: fujita.etsuro@lab.ntt.co.jp
Subject: Re: postgres_fdw: oddity in costing aggregate pushdown paths
In-Reply-To: <5C0639B7.1080006@lab.ntt.co.jp>
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