Re: generic plans and "initial" pruning

On 2022-Dec-09, Amit Langote wrote:

> On Wed, Dec 7, 2022 at 4:00 AM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> > I find the API of GetCachedPlans a little weird after this patch.

> David, in his Apr 7 reply on this thread, also sounded to suggest
> something similar.
>
> Hmm, I was / am not so sure if GetCachedPlan() should return something
> that is not CachedPlan. An idea I had today was to replace the
> part_prune_results_list output List parameter with, say,
> QueryInitPruningResult, or something like that and put the current
> list into that struct. Was looking at QueryEnvironment to come up
> with *that* name. Any thoughts?

Remind me again why is part_prune_results_list not part of struct
CachedPlan then? I tried to understand that based on comments upthread,
but I was unable to find anything.

(My first reaction to your above comment was "well, rename GetCachedPlan
then, maybe to GetRunnablePlan", but then I'm wondering if CachedPlan is
in any way a structure that must be "immutable" in the way parser output
is. Looking at the comment at the top of plancache.c it appears to me
that it isn't, but maybe I'm missing something.)

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"The Postgresql hackers have what I call a "NASA space shot" mentality.
Quite refreshing in a world of "weekend drag racer" developers."
(Scott Marlowe)