On 2020-Jul-27, Scott Ribe wrote:
> > On Jul 27, 2020, at 4:00 PM, Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
> >
> > I don't quite understand why is it that a table with 1000 partitions
> > means that JIT compiles the thing 1000 times. Sure, it is possible that
> > some partitions have a different column layout, but it seems an easy bet
> > that most cases are going to have identical column layout, and so tuple
> > deforming can be shared. (I'm less sure about sharing a compile of an
> > expression, since the varno would vary. But presumably there's a way to
> > take the varno as an input value for the compiled expr too?) Now I
> > don't actually know how this works so please correct if I misunderstand
> > it.
>
> I'm guessing it's because of inlining. You could optimize a function
> that takes parameters, no problem. But what's happening is inlining,
> with parameters, then optimizing.
Are you saying that if you crank jit_inline_above_cost beyond this
query's total cost, the problem goes away?
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
