Re: database design method

From: Paul Vernon <paul.vernon_at_ukk.ibmm.comm>
Date: Mon, 11 Nov 2002 18:42:32 -0000
Message-ID: <aqotob$thm$1@sp15at20.hursley.ibm.com>

"Jan Hidders" <hidders_at_REMOVE.THIS.uia.ua.ac.be> wrote in message news:3dcff3de$1_at_news.uia.ac.be...
> If you want to be precise it should be for example:
>
> ( node-value : "book",
> subtrees : { ( node-value : "chapter1", subtrees : {} ),
> ( node-value : "chapter2", subtrees : {} ) } )
>
> and in this value the following nested values would also belong to the type:
>
> ( node-value : "chapter1", subtrees: {} )
>
> ( node-value : "chapter2", subtrees: {} )
>
> Note that his example is a bit artificial because the chapters are more
> likely to be list then a set, but that is besides the point.

So {} is a valid value for this tuple type. Excuse my ignorance, but what is it? A tuple with two attributes but no 'rows'?!

Regards
Paul Vernon
Business Intelligence, IBM Global Services Received on Mon Nov 11 2002 - 12:42:32 CST