Re: parallel mode and parallel contexts

On Wed, Feb 4, 2015 at 9:40 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> On Fri, Jan 30, 2015 at 12:08 PM, Robert Haas <robertmhaas(at)gmail(dot)com>
wrote:
> > Here's a new version. Andres mentioned previously that he thought it
> > would be a good idea to commit the addition of
> > BackgroundWorkerInitializeConnectionByOid() separately, as he's had
> > cause to want it independently of the rest of this stuff. It would be
> > useful for pg_background, too. So I've broken that out into a
> > separate patch here (bgworker-by-oid.patch) and will commit that RSN
> > unless somebody thinks it's a bad idea for some reason. AFAICS it
> > should be uncontroversial.
>
> This is now done.
>
> The main patch needed some updating in light of Andres's recent
> assault on ImmediateInterruptOK (final result: Andres 1-0 IIOK) so
> here's a new version.
>

I think we should expose variable ParallelWorkerNumber (or if you don't
want to expose it then atleast GetParallel* function call is required to get
the value of same), as that is needed for external applications wherever
they want to allocate something for each worker, some examples w.r.t
parallel seq scan patch are each worker should have separate tuple
queue and probably for implementation of Explain statement also we
might need it.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com