Re: Allow parallel plan for referential integrity checks?

On Mon, 12 Dec 2022 at 22:06, Frédéric Yhuel <frederic(dot)yhuel(at)dalibo(dot)com> wrote:
>
>
>
> On 12/11/22 06:29, Ian Lawrence Barwick wrote:
> > 2022年7月26日(火) 20:58 Frédéric Yhuel <frederic(dot)yhuel(at)dalibo(dot)com>:
> >>
> >>
> >>
> >> On 4/14/22 14:25, Frédéric Yhuel wrote:
> >>>
> >>>
> >>> On 3/19/22 01:57, Imseih (AWS), Sami wrote:
> >>>> I looked at your patch and it's a good idea to make foreign key
> >>>> validation
> >>>> use parallel query on large relations.
> >>>>
> >>>> It would be valuable to add logging to ensure that the ActiveSnapshot
> >>>> and TransactionSnapshot
> >>>> is the same for the leader and the workers. This logging could be
> >>>> tested in the TAP test.
> >>>>
> >>>> Also, inside RI_Initial_Check you may want to set max_parallel_workers to
> >>>> max_parallel_maintenance_workers.
> >>>>
> >>>> Currently the work_mem is set to maintenance_work_mem. This will also
> >>>> require
> >>>> a doc change to call out.
> >>>>
> >>>> /*
> >>>> * Temporarily increase work_mem so that the check query can be
> >>>> executed
> >>>> * more efficiently. It seems okay to do this because the query
> >>>> is simple
> >>>> * enough to not use a multiple of work_mem, and one typically
> >>>> would not
> >>>> * have many large foreign-key validations happening
> >>>> concurrently. So
> >>>> * this seems to meet the criteria for being considered a
> >>>> "maintenance"
> >>>> * operation, and accordingly we use maintenance_work_mem.
> >>>> However, we
> >>>>
> >>>
> >>> Hello Sami,
> >>>
> >>> Thank you for your review!
> >>>
> >>> I will try to do as you say, but it will take time, since my daily job
> >>> as database consultant takes most of my time and energy.
> >>>
> >>
> >> Hi,
> >>
> >> As suggested by Jacob, here is a quick message to say that I didn't find
> >> enough time to work further on this patch, but I didn't completely
> >> forget it either. I moved it to the next commitfest. Hopefully I will
> >> find enough time and motivation in the coming months :-)
> >
> > Hi Frédéric
> >
> > This patch has been carried forward for a couple more commitfests since
> > your message; do you think you'll be able to work on it further during this
> > release cycle?
> >
>
> Hi Ian,
>
> I've planned to work on it full time on week 10 (6-10 March), if you
> agree to bear with me. The idea would be to bootstrap my brain on it,
> and then continue to work on it from time to time.

I have moved this to Mar commitfest as the patch update is expected to
happen during March commitfest.

Regards,
Vignesh