Re: pgsql: Add a new GUC and a reloption to enable inserts in parallel-mode

On Fri, Mar 26, 2021 at 11:07 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Wed, Mar 24, 2021 at 12:14 AM Andres Freund <andres(at)anarazel(dot)de> wrote:
> >
> >
> > Shouldn't we have this in IndexOptInfo already?
> >
>
> No, because I think we don't build IndexOptInfo for target tables
> (tables in which insert is performed). It is only built for tables to
> scan. However, I think here we could cache parallel-safety info in the
> index rel descriptor and can use it for next time. This will avoid
> checking expressions each time.
>

On further investigation, it seems we can't rely on the cached
information of parallel-safety in rel descriptor because we don't
invalidate it if someone changes function property say from safe to
unsafe or vice-versa. We need to think of some other idea here, simply
caching rel descriptors won't work. I think we need to further discuss
this topic on -hackers.

--
With Regards,
Amit Kapila.