Re: Schema variables - new implementation for Postgres 15

so 18. 5. 2024 v 18:31 odesílatel Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
napsal:

> On 2024-Jan-30, Dmitry Dolgov wrote:
>
> > Yep, in this constellation the implementation holds much better (in
> > terms of memory) in my create/let/drop testing.
> >
> > I've marked the CF item as ready for committer, but a note for anyone
> > who would like to pick up it from here -- we're talking about first 5
> > patches here, up to the memory cleaning after DROP VARIABLE. It doesn't
> > mean the rest is somehow not worth it, but I believe it's a good first
> > step.
>
> Hmm, I think patch 16 is essential, because the point of variable shadowing
> is a critical aspect of how the whole thing works. So I would say that
> a first step would be those first five patches plus 16.
>

I'll move patch 16 to 6 position

Regards

Pavel

>
> I want to note that when we discussed this patch series at the dev
> meeting in FOSDEM, a sort-of conclusion was reached that we didn't want
> schema variables at all because of the fact that creating a variable
> would potentially change the meaning of queries by shadowing table
> columns. But this turns out to be incorrect: it's _variables_ that are
> shadowed by table columns, not the other way around.
>
> --
> Álvaro Herrera PostgreSQL Developer —
> https://www.EnterpriseDB.com/
> "No hay ausente sin culpa ni presente sin disculpa" (Prov. francés)
>