Re: Parallel copy

On Wed, Nov 11, 2020 at 10:42 PM vignesh C <vignesh21(at)gmail(dot)com> wrote:
>
> On Tue, Nov 10, 2020 at 7:27 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> >
> > On Tue, Nov 10, 2020 at 7:12 PM vignesh C <vignesh21(at)gmail(dot)com> wrote:
> > >
> > > On Tue, Nov 3, 2020 at 2:28 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > > >
> > >
> > > I have worked to provide a patch for the parallel safety checks. It
> > > checks if parallely copy can be performed, Parallel copy cannot be
> > > performed for the following a) If relation is temporary table b) If
> > > relation is foreign table c) If relation has non parallel safe index
> > > expressions d) If relation has triggers present whose type is of non
> > > before statement trigger type e) If relation has check constraint
> > > which are not parallel safe f) If relation has partition and any
> > > partition has the above type. This patch has the checks for it. This
> > > patch will be used by parallel copy implementation.
> > >
> >
> > How did you ensure that this is sufficient? For parallel-insert's
> > patch we have enabled parallel-mode for Inserts and ran the tests with
> > force_parallel_mode to see if we are not missing anything. Also, it
> > seems there are many common things here w.r.t parallel-insert patch,
> > is it possible to prepare this atop that patch or do you have any
> > reason to keep this separate?
> >
>
> I have done similar testing for copy too, I had set force_parallel
> mode to regress, hardcoded in the code to pick parallel workers for
> copy operation and ran make installcheck-world to verify. Many checks
> in this patch are common between both patches, but I was not sure how
> to handle it as both the projects are in-progress and are being
> updated based on the reviewer's opinion. How to handle this?
> Thoughts?
>

I have not studied the differences in detail but if it is possible to
prepare it on top of that patch then there shouldn't be a problem. To
avoid confusion if you want you can always either post the latest
version of that patch with your patch or point to it.

--
With Regards,
Amit Kapila.