Re: patch for check constraints using multiple inheritance

Yeb Havinga <yebhavinga@gmail.com> writes:
> Regard the following lattice (direction from top to bottom):

> 1
> |\
> 2 3
>  \|\
>   4 5
>    \|
>     6

> When adding a constraint to 1, the proper coninhcount for that 
> constraint on relation 6 is 2. But the code currently counts to 3, since 
> 6 is reached by paths 1-2-4-5, 1-3-4-6, 1-3-5-6.

Mph.  I'm not sure that 3 is wrong.  You have to consider what happens
during a DROP CONSTRAINT, which as far as I saw this patch didn't
address.
        regards, tom lane