Re: database design method

From: Paul Vernon <paul.vernon_at_ukk.ibmm.comm>
Date: Sun, 17 Nov 2002 22:55:20 -0000
Message-ID: <araiqp$tlc$1_at_sp15at20.hursley.ibm.com>


"Paul Vernon" <paul.vernon_at_ukk.ibmm.comm> wrote in message news:aqoeks$vcs$1_at_sp15at20.hursley.ibm.com...
> "Jan Hidders" <hidders_at_REMOVE.THIS.uia.ua.ac.be> wrote in message
> news:3dcda833$1_at_news.uia.ac.be...
> > So can I abuse you a little more as my tutorial-D tutor? :-) Can I have
> > recursive types? For example (probably not the right syntax, but I think
you
> > will understand what I mean):
> >
> > TYPE Tree = TUPLE { NODE-VALUE STRING, SUBTREES RELATION { TREE Tree } }
>
> I don't have the book on me today, but I'm sure that they explicitly
disallow
> such recursive definition of both tuples and relvars.

I had a look in the book (you should get a copy Jan :-), but could find no comment either way on recursively defined types. That suggest to me that they have not occasioned to consider such a possibility.

Regards
Paul Vernon
Business Intelligence, IBM Global Services Received on Sun Nov 17 2002 - 23:55:20 CET

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