Re: what are keys and surrogates?
Date: Wed, 9 Jan 2008 08:07:25 -0800 (PST)
Message-ID: <f4a295e5-5fbf-4cd8-a5e3-3c6ffa55a1de_at_s12g2000prg.googlegroups.com>
On Jan 9, 1:25 pm, Marshall <marshall.spi..._at_gmail.com> wrote:
> This issue goes away if we relax 1NF and allow attributes that are
In addition to my previous post, I wish to add another comment
regarding my suspicion with RVAs. The tuples of a relation are
supposed to represent facts, but what does it mean when a relation
merely represents a value? Isn't the RM meant to have some close
association with FOPL?
> lists or relations. This gives us nested structures. (Nested relations
> are not particularly controversial around here.)
It seems to me there is a fundamental difference between
IMO the RM is very practical for a) but not generally suitable for b).
If you want to describe a composite data structure indirectly using a large collection of propositions then expect to need to go on a naming spree in order to refer to the parts of the data structure that are related to each other!
If on the other hand you use nested relations to directly represent the data structure (so as to avoid the need for meaningless identifiers) then you're not even choosing to represent it using a large collection of propositions at all, and that is contrary to what the RM is all about. Received on Wed Jan 09 2008 - 17:07:25 CET