Re: utility commands benefiting from parallel plan

On Tue, Feb 28, 2017 at 12:48 PM, Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com>
wrote:

>
>
> On Sat, Feb 25, 2017 at 3:21 AM, Robert Haas <robertmhaas(at)gmail(dot)com>
> wrote:
>
>> On Fri, Feb 24, 2017 at 11:43 AM, Haribabu Kommi
>> <kommi(dot)haribabu(at)gmail(dot)com> wrote:
>> > Here I attached an implementation patch that allows
>> > utility statements that have queries underneath such as
>> > CREATE TABLE AS, CREATE MATERIALIZED VIEW
>> > and REFRESH commands to benefit from parallel plan.
>> >
>> > These write operations not performed concurrently by the
>> > parallel workers, but the underlying query that is used by
>> > these operations are eligible for parallel plans.
>> >
>> > Currently the write operations are implemented for the
>> > tuple dest types DestIntoRel and DestTransientRel.
>> >
>> > Currently I am evaluating other write operations that can
>> > benefit with parallelism without side effects in enabling them.
>> >
>> > comments?
>>
>> I think a lot more work than this will be needed. See:
>>
>> https://www.postgresql.org/message-id/CA+TgmoZC5ft_t9uQWSO5_
>> 1vU6H8oVyD=zyuLvRnJqTN==fvnhg(at)mail(dot)gmail(dot)com
>>
>> ...and the discussion which followed.
>>
>
>
> Thanks for the link.
> Yes, it needs more work to support parallelism even for
> queries that involved in write operations like INSERT,
> DELETE and UPDATE commands.
>

This patch is marked as "returned with feedback" in the ongoing
commitfest.

The proposed DML write operations patch is having good number
of limitations like triggers and etc, but the utility writer operations
patch is in a good shape in my view to start supporting write operations.
This is useful for materialized view while refreshing the data.

Do you find any problems/missings in supporting parallel plan for utility
commands with the attached update patch? Or is it something
like supporting all write operations at once?

Regards,
Hari Babu
Fujitsu Australia