Re: Question about inheritance

I have added this thread to TODO.detail/inheritance.

> > "Christopher Kings-Lynne" <chriskl(at)familyhealth(dot)com(dot)au> writes:
> > > Am I misunderstanding how the mechanism works, or is this a big, not
> easily
> > > solved, problem?
> >
> > The latter. Check the list archives for previous debates about this.
> > It's not real clear whether an inherited primary key should be expected
> > to be unique across the whole inheritance tree, or only unique per-table
> > (IIRC, plausible examples have been advanced for each case). If we want
> > uniqueness across multiple tables, it'll take considerable work to
> > create an index mechanism that'd enforce it.
> >
> IMHO current behaviour of PostgreSQL with inherited PK, FK, UNIQUE is
> simply
> bug not only from object-oriented but even object-related point of view.
> Now
> I can violate parent PK by inserting duplicate key in child!
>
> Inherited tables should honours all constraints from parent. If I change
> some constraint (seems only FK, but not PK or UNIQUE) I should be able to
> do
> it in more restrictive manner. For example, two base table is connected via
> FK. I can change such FK in childs from base1->base2 to child1->child2 (or
> child3) but not to child1->not_inherited_from_base2. CHECK, DEFAULT, NOT
> NULL are more free to changes, isn't it?
>
> IMHO last message in doc/TODO.details/inheritance from Oliver Elphick is a
> good direction for implementing with exception on more rectrictive child FK
> constraint (p.3 of message).
>
> As for me, I was pushed to rollback to scheme with no inheritance at all in
> my project for now. So I'm very interesting in implementing of right
> inheritance and I wanted to ask similar question in one of the lists in
> near
> future.
>
> Regards,
> Dmitry
>
>
>
>
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