Re: [HACKERS] Tutorial

On Fri, Jul 23, 2004 at 09:03:30AM +0200, Peter Eisentraut wrote:
> Tom Lane wrote:
> > Robert Treat <xzilla(at)users(dot)sourceforge(dot)net> writes:
> > > +1/2 (Since I don't like inheritence)
> > >
> > > IMHO we ought to try to keep the _tutorial_ free of things that
> > > are generally considered against relational design.
> >
> > Where is it written that inheritance is against relational design?
>
> I would venture that it is nowhere written that it is part of
> relational design. It is, however, unambiguously part of
> object-relational design, if that's what we're aiming for.

I see I have put my foot in it again. Please bear with me here.
Object-relational in general is not broken and is being worked on.
Custom data-types, custom aggregates, etc., etc. are working just
great, and lots of people use them.

What *is* broken is table inheritance, and the docs need to reflect
this.

If the parent table has a foreign key to another table foo, CASCADEing
DELETEs on foo leave ghost entries in the tables with inheritance.
Please find enclosed a repro, which demonstrates the problem on CVS
tip and 7.4.3.

Just an FYI, I first discovered this problem in a payment system.

Cheers,
D
--
David Fetter david(at)fetter(dot)org http://fetter.org/
phone: +1 510 893 6100 mobile: +1 415 235 3778

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