Re: Add parameter jit_warn_above_fraction

On Wed, 30 Mar 2022 at 14:48, Andres Freund <andres@anarazel.de> wrote:
>
> On 2022-03-30 14:30:32 +1300, David Rowley wrote:
> > Maybe nodes below an Append/MergeAppend with run-time pruning could compile
> > on-demand and other nodes up-front.  Or maybe there's no problem with making
> > everything on-demand.
>
> Yea, that could work. The expressions for one "partition query" would still
> have to be emitted at once. For each such subtree we should make a separate
> costing decision. But I think an additional "will be executed" sub-node is a
> different story, the threshold shouldn't be done on a per-node basis.  That
> partitioning of the plan tree is kind of what I was trying to get at...

Maybe this point is moot if we get something like [1]. It might mean
that run-time pruning would happen early enough that we could just JIT
compile non-pruned subnodes.

David

[1] https://commitfest.postgresql.org/37/3478/