Horton

Re: Missing docs for new enable_group_by_reordering GUC

Pavel Borisov <pashkin.elfe@gmail.com>

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From: Pavel Borisov <pashkin.elfe@gmail.com>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Andrei Lepikhov <lepihov@gmail.com>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2024-06-18T13:13:57Z
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.

>
> 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

Regards,
Pavel