Re: AW: Postgresql OO Patch

"Robert B. Easter" wrote:

> > Imho this alone more than justifies the patch.
> > We should also change our keyword "inherits" to "under".
> >
> 
> I don't agree.  UNDER only provides for single inheritance according to spec.
> Making it multiple inherit would break UNDER's basic idea of enabling hierarchy
> trees that contain subtables under a single maximal supertable. 

I don't see that it's a "basic idea". I see it as crippled subset of
SQL3-94.

> is ok too.  But the meaning is different than above.  It creates an independent
> child table that is not contained under either parent so that the parents can
> be dropped.  

I wouldn't like to define an object model in terms of what happens when
the meta-data is modified.

> You use UNDER when the child/subtabe to share the exact same
> physical PRIMARY KEY of the SUPERTABLE.  In inherit, the child inherits a
> composite key from the parents, but that key is new physically, not the same
> physically as any parents.

Issues like primary keys are the sort of stuff that probably kept the
committee arguing long enough they were too lazy to come to a decision.
Myself, I'm not too interested in primary keys since they are not a very
OO idea anyway.