Re: Allow placeholders in ALTER ROLE w/o superuser

Hey Alexander,

Looks like your latest patch addresses the original issue I posted!

So now I can create a placeholder with the USERSET modifier without a
superuser, while non-USERSET placeholders still require superuser:

```sql
create role foo noinherit;
set role to foo;

alter role foo set prefix.bar to true user set;
ALTER ROLE

alter role foo set prefix.baz to true;
ERROR:  permission denied to set parameter "prefix.baz"

set role to postgres;
alter role foo set prefix.baz to true;
ALTER ROLE
```

Also USERSET gucs are marked(`(u)`) on `pg_db_role_setting`:

```sql
select * from pg_db_role_setting ;
 setdatabase | setrole |              setconfig
-------------+---------+--------------------------------------
           0 |   16384 | {prefix.bar(u)=true,prefix.baz=true}
```

Which I guess avoids the need for adding columns to `pg_catalog` and makes
the "fix" simpler.

So from my side this all looks good!

Best regards,
Steve

On Sun, 20 Nov 2022 at 12:50, Alexander Korotkov <aekorotkov@gmail.com>
wrote:

> .On Sun, Nov 20, 2022 at 8:48 PM Alexander Korotkov
> <aekorotkov@gmail.com> wrote:
> > I've drafted a patch implementing ALTER ROLE ... SET ... TO ... USER SET
> syntax.
> >
> > These options are working only for USERSET GUC variables, but require
> > less privileges to set.  I think there is no problem to implement
> >
> > Also it seems that this approach doesn't conflict with future
> > privileges for USERSET GUCs [1].  I expect that USERSET GUCs should be
> > available unless explicitly REVOKEd.  That mean we should be able to
> > check those privileges during ALTER ROLE.
> >
> > Opinions on the patch draft?
> >
> > Links
> > 1.
> https://mail.google.com/mail/u/0/?ik=a20b091faa&view=om&permmsgid=msg-f%3A1749871710745577015
>
> Uh, sorry for the wrong link.  I meant
> https://www.postgresql.org/message-id/2271988.1668807706@sss.pgh.pa.us
>
> ------
> Regards,
> Alexander Korotkov
>