Re: [HACKERS] Minor correction in alter_table.sgml

Amit,

* Amit Langote (amitlangote09@gmail.com) wrote:
> On Fri, Dec 23, 2016 at 12:07 AM, Stephen Frost <sfrost@snowman.net> wrote:
> > * Tom Lane (tgl@sss.pgh.pa.us) wrote:
> >> (Of course, maybe the question we ought to be asking here is why
> >> ATTACH/DETACH PARTITION failed to go with the flow and be a
> >> combinable action.)
> >
> > I did wonder that myself but havne't looked at the code.  I'm guessing
> > there's a reason it's that way.
>
> I thought the possibility of something like the following happening
> should be avoided:
>
> alter table p attach partition p1 for values in (1, 2, 3), add b int;
> ERROR:  child table is missing column "b"

Sure, but what about something like:

alter table p attach partition p1 for values in (1, 2, 3), alter column
b set default 1; ?

> Although, the same can be said about ALTER TABLE child INHERIT parent, I guess.

Certainly seems like that's an indication that there are use-cases for
allowing it then.  We do tend to avoid arbitrary restrictions and if
there isn't really anything code-level for ATTACH/DETACH partition to be
this way then we change it to be allowed.

Thanks!

Stephen