Re: Schema variables - new implementation for Postgres 15

Hi

po 20. 5. 2024 v 9:11 odesílatel Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
napsal:

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> 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.
>>
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> I'll move patch 16 to 6 position
>

reorderd set of patches - I moved forward plpgsql-tests.patch and
GUC-session_variables_ambiguity_warning.patch

0006-plpgsql-tests.patch
0007-GUC-session_variables_ambiguity_warning.patch

no other changes

Regards

Pavel

>
> 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)
>>
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