Re: Schema variables - new implementation for Postgres 15

Hi

A bit more work seems to be needed for deparsing session variables:
>
> # create variable myvar text;
> CREATE VARIABLE
>
> # create view myview as select myvar;
> CREATE VIEW
>
> # \d+ myview
> View "public.myview"
> Column | Type | Collation | Nullable | Default | Storage | Description
> --------+------+-----------+----------+---------+----------+-------------
> myvar | text | | | | extended |
> View definition:
> SELECT myvar AS myvar;
>
> There shouldn't be an explicit alias I think.
>

I check this issue, and I afraid so it is not fixable. The target list
entry related to session variable has not some magic value like ?column?
that can be used for check if tle->resname is implicit or explicit

And in this time I cannot to use FigureColname because it doesn't work with
transformed nodes. More - the Param node can be nested in SubscriptingRef
or FieldSelect. It doesn't work perfectly now. See following example:

create type xt as (a int, b int);
create view b as select (10, ((random()*100)::int)::xt).b;
\d+ b
SELECT (ROW(10, (random() * 100::double precision)::integer)::xt).b AS b;

Regards

Pavel