Re: Parallel INSERT (INTO ... SELECT ...)

On Fri, Sep 25, 2020 at 9:11 AM Greg Nancarrow <gregn4422(at)gmail(dot)com> wrote:
>
> > > What if this
> > > ends up being invoked from inside C code?
> > >
> >
> > I think it shouldn't be a problem unless one is trying to do something
> > like insert into foreign key table. So, probably we can have an Assert
> > to catch it if possible. Do you have any other idea?
> >
>
> Note that the planner code updated by the patch does avoid creating a
> Parallel INSERT plan in the case of inserting into a table with a
> foreign key (so commandIds won't be created in the parallel-worker
> code).
> I'm not sure how to distinguish the "invoked from inside C code" case though.
>

I think if possible we can have an Assert to check if it is a
parallel-worker and relation has a foreign-key. Similarly, we can
enhance the check for any other un-safe use. This will prevent the
illegal usage of inserts via parallel workers.

--
With Regards,
Amit Kapila.