Re: Schema variables - new implementation for Postgres 15

Hi

8) immutable variables without a default value
>
> IMO this case should not be allowed. On 2021/08/29 you wrote:
>
> I thought about this case, and I have one scenario, where this
> behaviour can be useful. When the variable is declared as IMMUTABLE
> NOT NULL without not null default, then any access to the content of
> the variable has to fail. I think it can be used for detection,
> where and when the variable is first used. So this behavior is
> allowed just because I think, so this feature can be interesting for
> debugging. If this idea is too strange, I have no problem to disable
> this case.
>

I checked code, and this case is disallowed already

postgres=# CREATE IMMUTABLE VARIABLE xx AS int NOT NULL;
ERROR: IMMUTABLE NOT NULL variable requires default expression

Regards

Pavel