Horton

Re: Missing docs for new enable_group_by_reordering GUC

Alexander Korotkov <aekorotkov@gmail.com>

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From: Alexander Korotkov <aekorotkov@gmail.com>
To: Pavel Borisov <pashkin.elfe@gmail.com>
Cc: Andrei Lepikhov <lepihov@gmail.com>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2024-06-19T01:27:31Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add doc entry for the new GUC paramenter enable_group_by_reordering

  2. Explore alternative orderings of group-by pathkeys during optimization.

Attachments

On Tue, Jun 18, 2024 at 4:14 PM Pavel Borisov <pashkin.elfe@gmail.com> wrote:
>> Controls if the query planner will produce a plan which will provide <literal>GROUP BY</literal> keys presorted in the order of keys of a child node of the plan, such as an index scan. When disabled, the query planner will produce a plan with <literal>GROUP BY</literal> keys only reordered to match
>> the <literal>ORDER BY</literal> clause, if any. When enabled, the planner will try to produce a more efficient plan. The default value is on.
> A correction of myself: presorted -> sorted, reordered ->sorted

Thank you for your review.  I think all of this make sense.  Please,
check the revised patch attached.

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Regards,
Alexander Korotkov
Supabase