Re: why not parallel seq scan for slow functions

On Sat, Jul 22, 2017 at 8:53 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
wrote:

> On Thu, Jul 13, 2017 at 7:38 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
> wrote:
> > On Wed, Jul 12, 2017 at 11:20 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
> wrote:
> >>
> >>
> >>
> >> Setting parallel_workers to 8 changes the threshold for the parallel to
> even
> >> be considered from parellel_tuple_cost <= 0.0049 to <= 0.0076. So it is
> >> going in the correct direction, but not by enough to matter.
> >>
> >
> > You might want to play with cpu_tuple_cost and or seq_page_cost.
> >
>
> I don't know whether the patch will completely solve your problem, but
> this seems to be the right thing to do. Do you think we should stick
> this for next CF?
>

It doesn't solve the problem for me, but I agree it is an improvement we
should commit.

Cheers,

Jeff