Thread: need more ALTER TABLE guards for typed tables

After some investigation I figured that I need to add two more checks
into the ALTER TABLE code to prevent certain types of direct changes to
typed tables (see attached patch).

But it's not clear to me whether such checks should go into the "Prep"
or the "Exec" phases.  Prep seems more plausible to me, but some
commands such as DropColumn don't have a Prep handler.  A clarification
would be helpful.

Excerpts from Peter Eisentraut's message of mié jul 21 15:18:58 -0400 2010:
> After some investigation I figured that I need to add two more checks
> into the ALTER TABLE code to prevent certain types of direct changes to
> typed tables (see attached patch).
> 
> But it's not clear to me whether such checks should go into the "Prep"
> or the "Exec" phases.  Prep seems more plausible to me, but some
> commands such as DropColumn don't have a Prep handler.  A clarification
> would be helpful.

I think if there's no Prep phase, you should add it.  I don't think it
makes sense to have this kind of check in Exec.

On ons, 2010-07-21 at 15:48 -0400, Alvaro Herrera wrote:
> Excerpts from Peter Eisentraut's message of mié jul 21 15:18:58 -0400 2010:
> > After some investigation I figured that I need to add two more checks
> > into the ALTER TABLE code to prevent certain types of direct changes to
> > typed tables (see attached patch).
> >
> > But it's not clear to me whether such checks should go into the "Prep"
> > or the "Exec" phases.  Prep seems more plausible to me, but some
> > commands such as DropColumn don't have a Prep handler.  A clarification
> > would be helpful.
>
> I think if there's no Prep phase, you should add it.  I don't think it
> makes sense to have this kind of check in Exec.

OK, here is my patch for this.  (should go into 9.0 and 9.1)