public inbox for [email protected]
help / color / mirror / Atom feedFrom: Teodor Sigaev <[email protected]>
To: Tomas Vondra <[email protected]>
To: Claudio Freire <[email protected]>
Cc: PostgreSQL-Dev <[email protected]>
Subject: Re: POC: GROUP BY optimization
Date: Thu, 7 Jun 2018 18:16:13 +0300
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<[email protected]>
<CAGTBQpbW+8jc8VRE39-3=cWSr8aGRRFds=s2BNQoh4ddO2X7UQ@mail.gmail.com>
<[email protected]>
<[email protected]>
<[email protected]>
>> Again agree. If we have fixed order of columns (ORDER BY) then we should not
>> try to reorder it. Current patch follows that if I didn't a mistake.
>>
>
> This part seems to be more a misunderstanding between me and Claudio. I believe
> Claudio was referring to the column order in a GROUP BY, not ORDER BY. In which
> case we don't add any Sort, of course.
I hope so
>
> I'm still opposed to adding arbitrary handicap to prioritize the order specified
> by user, for the reasons I explained before. We should aim to make the
> heuristics/costing reliable enough to make this unnecessary.
+1
--
Teodor Sigaev E-mail: [email protected]
WWW: http://www.sigaev.ru/
view thread (89+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected]
Subject: Re: POC: GROUP BY optimization
In-Reply-To: <[email protected]>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox