Re: ExecGather() + nworkers

On Mon, Jan 11, 2016 at 9:16 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
wrote:
> On Mon, Jan 11, 2016 at 3:14 AM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:
> >
> > On Sun, Jan 10, 2016 at 9:13 AM, Robert Haas <robertmhaas(at)gmail(dot)com>
wrote:
> > >> I'm not sure why the test for nworkers following the
> > >> LaunchParallelWorkers() call doesn't look like this, though:
> > >>
> > >> /* Set up tuple queue readers to read the results. */
> > >> if (pcxt->nworkers_launched > 0)
> > >> {
> > >> ...
> > >> }
> > >
> > > Hmm, yeah, I guess it could do that.
> >
> > That would make it clearer as an example.
> >
> > >> But going to this additional trouble (detecting no workers launched
on
> > >> the basis of !nworkers_launched) suggests that simply testing
> > >> nworkers_launched would be wrong, which AFAICT it isn't. Can't we
just
> > >> do that, and in so doing also totally remove the "for" loop shown
> > >> here?
> > >
> > > I don't see how the for loop goes away.
> >
> > I meant that some code in the "for" loop goes away. Not all of it.
> > Just the more obscure code. As I said, I'm mostly pointing this out
> > out of concern for making it clearer as example code.
> >
>
> Right, I can write a patch to do it in a way you are suggesting if you
> are not planning to do it.
>

Changed the code such that nworkers_launched gets used wherever
appropriate instead of nworkers. This includes places other than
pointed out above.

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