On Thu, Apr 6, 2023 at 1:06 PM Tom Lane <t...@sss.pgh.pa.us> wrote:
> This: > > > +#if 0 > > /* If any limit was set to zero, the user doesn't want a > > parallel scan. */ > > if (parallel_workers <= 0) > > return; > > +#endif > > seems like it adds a lot of new paths with a lot lower chance > of win, but maybe we could tighten the conditions to improve > the odds? Seems it wins if the parallel scan becomes part of a hash join in final plan. I wonder if we have a way to know that in this early stage. BTW, zero parallel_workers seems would break some later assumptions, so we may need to give it a meaningful number if we want to do in this way. Thanks Richard
