Re: Allow DISTINCT to use Incremental Sort

From: David Rowley <dgrowleyml(at)gmail(dot)com>
To: Richard Guo <guofenglinux(at)gmail(dot)com>
Cc: PostgreSQL Developers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: Allow DISTINCT to use Incremental Sort
Date: 2023-01-10 21:29:06
Message-ID: CAApHDvpJZtouyh-sF=xtmNCjj683RQPJ=rZataYJzo6V7UMm1Q@mail.gmail.com
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On Tue, 10 Jan 2023 at 16:07, Richard Guo <guofenglinux(at)gmail(dot)com> wrote:
> Sorry I didn't make myself clear. I mean currently on HEAD in planner.c
> from line 4847 to line 4857, we have the code to make sure we always use
> the more rigorous clause for explicit-sort case. I think this code is
> not necessary, because we have already done that in line 4791 to 4796,
> for both DISTINCT ON and standard DISTINCT.

Thanks for explaining. I'm unsure if that code ever did anything
useful, but I agree that it does nothing now.

>> I've attached an updated patch
>
>
> The patch looks good to me.

Thanks for having another look. I've now pushed the patch.

David

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