Re: tracking inherited columns (was: patch for check constraints using multiple inheritance)

Tom Lane wrote:
> Yeb Havinga <yebhavinga(at)gmail(dot)com> writes:
>
>> A.a_column B.a_column
>> | /
>> v v
>> C.a_column
>>
>> C inherits from A and B.
>>
>
> Well, if A and B inherited the column from a common ancestor, he can
> easily do that. If not, maybe he should have thought harder before he
> started. I do NOT agree that issuing a rename against C is a sane way
> of dealing with this.
>

Ok, I understand the intuition behind not wanting this kind of update.

The root cause seems to center around multiple inheritance of the same
column without a common ancestor. Another way to approach the problem,
is to prevent the user to create a setup, i.e. when adding a column to B
that already exists in A, or when adding a inheritance relation A-C or
B-c, if A and B share column names. He could then get a hint he should
add a common ancestor with that column. This preemptively prevents
problems with renames and other changes.

/me ducks

regards,
Yeb Havinga