Re: Parallel sec scan in plpgsql

Поиск
Список
Период
Сортировка
От Robert Haas
Тема Re: Parallel sec scan in plpgsql
Дата
Msg-id CA+TgmoY_uNECNPX1BaC-zOpFocaEoSThaeqVMmGvDV18k2j+eA@mail.gmail.com
обсуждение исходный текст
Ответ на Re: Parallel sec scan in plpgsql  (Amit Kapila <amit.kapila16@gmail.com>)
Ответы Re: Parallel sec scan in plpgsql  (Amit Kapila <amit.kapila16@gmail.com>)
Список pgsql-hackers
On Tue, Sep 20, 2016 at 9:24 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> I think here point is that for any case where there is count of rows
> to be selected, we disable parallelism.  There are many genuine cases
> like select count(*) into cnt ... which will run to completion, but as
> plpgsql passes row count to be 1 or 2, it doesn't enter parallel mode.
> There are couple other cases like that.  Do you see a reason for not
> enabling parallelism for such cases?

If we can somehow know that the rowcount which is passed is greater
than or equal to the actual number of rows which will be generated,
then it's fine to enable parallelism.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: Parallel sec scan in plpgsql
Следующее
От: Robert Haas
Дата:
Сообщение: Re: Parallel sec scan in plpgsql