Re: Extract numeric filed in JSONB more effectively

On Sat, Aug 19, 2023 at 3:09 AM Chapman Flack <chap(at)anastigmatix(dot)net> wrote:

> On 2023-08-18 14:50, Chapman Flack wrote:
> > Now, my guess is EXPLAIN is complaining when it sees the Const
> > of type internal, and doesn't know how to show that value.
> > Perhaps makeRelabelType is the answer there, too: what if the
> > Const has Oid type, so EXPLAIN can show it, and what's inserted
> > as the function argument is a relabel node saying it's internal?

>
Simply changing the Const to be of type Oid makes EXPLAIN happy,
> and nothing ever says "hey, why are you passing this oid for an
> arg that wants internal?". This is without adding any relabel
> nodes anywhere.
>

Highlighting the user case of makeRelableType is interesting! But using
the Oid directly looks more promising for this question IMO, it looks like:
"you said we can put anything in this arg, so I put an OID const here",
seems nothing is wrong. Compared with the makeRelableType method,
I think the current method is more straightforward. Compared with
anyelement, it avoids the creation of makeDummyConst which I'm not
sure the implementation is alway correct. So I am pretty inclined to this
way!

v10 attached.

--
Best Regards
Andy Fan