Re: BUG #18330: The query planner chooses the wrong plan when using the parallel aggregation function

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: BUG #18330: The query planner chooses the wrong plan when using the parallel aggregation function
Дата
Msg-id 4148241.1707092200@sss.pgh.pa.us
обсуждение исходный текст
Ответ на BUG #18330: The query planner chooses the wrong plan when using the parallel aggregation function  (PG Bug reporting form <noreply@postgresql.org>)
Список pgsql-bugs
Дерево обсуждения 
PG Bug reporting form <noreply@postgresql.org> writes:
> Below is an example of queries. It shows that the query planner chooses
> sequential aggregation instead of parallel, although limit should not have
> affected this.

On what grounds do you assert that LIMIT can be parallelized?
AFAICS it has to be done by a single process to ensure that the
limit is enforced accurately.  So LIMIT below an aggregation
removes the opportunity to parallelize the aggregation.

            regards, tom lane

В списке pgsql-bugs по дате отправления:

Предыдущее
От: PG Bug reporting form
Дата:
Сообщение: BUG #18330: The query planner chooses the wrong plan when using the parallel aggregation function
Следующее
От: Masahiko Sawada
Дата:
Сообщение: Re: Potential data loss due to race condition during logical replication slot creation