Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!linus!alliant!merk!uvmark!jim
From: jim@uvmark.uucp (Jim Todhunter)
Newsgroups: comp.databases
Subject: Re: Relational Databases
Message-ID: <1991Jun08.124337.29813@uvmark.uucp>
Date: 8 Jun 91 12:43:37 GMT
References: <6822@vela.acs.oakland.edu> <1991Jun07.063749.7904@chinet.chi.il.us>
Organization: Vmark Software, Inc.
Lines: 30

In article <1991Jun07.063749.7904@chinet.chi.il.us> dhartung@chinet.chi.il.us (Dan Hartung) writes:
>mebrenna@vela.acs.oakland.edu (Leonardo) writes:
>>Does anyone have a good definition of a Relational Database, and a
>>possible example?
>
>[... Stuff deleted ...]
>
>Basically, a relational database is one that has been "normalized", that
>is, taken through (at minimum) first, second, and third normal forms.
>These "normal forms" are the processes of eliminating repeating data
>in favor of index keys.
>
>[... stuff deleted ...]

Just a minor correction to this posting.  A relational database does NOT
need to be normalized.  In fact, some of the most interesting current
research is the area of NFNF (non first normal form) relational models.
This is a very active area of investigation because there are serious
deficiencies in the first normal form model.  While Codd dismisses NFNF
and OO model out of hand, most others, including Date, do not share his
view.  (It is interesting to note that CODD's recent book reads very much
like a dinosaur's defense of his raison d'etre.)  NFNF models can also use
indices.  The truth is normalization is merely a convenience for that
database theorist, making the mathemetical proofs easier.

-- 
 James W. Todhunter, Manager, Software Development
 Vmark Software, Inc., 5 Strathmore Road, Natick, MA  01760, USA
 Internet: uvmark!jim@merk.com, UUCP: uunet!merk!uvmark!jim
 Phone: (508) 655-3700, Fax: (508) 655-8395, Telex: 5101011619 VMARKUNIVERS