Path: utzoo!mnetor!tmsoft!torsqnt!jarvis.csri.toronto.edu!rutgers!psuvax1!psuvm!uh2
From: UH2@PSUVM.BITNET (Lee Sailer)
Newsgroups: comp.databases
Subject: Re: data base tools
Message-ID: <89262.132723UH2@PSUVM.BITNET>
Date: 19 Sep 89 17:27:23 GMT
References: <6403@latcs1.oz>
Organization: Penn State University
Lines: 31

In article <6403@latcs1.oz>, ping@latcs1.oz (Ping Li) says:
>
>	Wondering if there are any tools available that
>
>		1) construct a relational data model;
>
>		2) and such a model should be either a 4th NORMAL FORM
>		   or a 3rd NORMAL FORM.
>
>	
>	Thank you in advance.


Good question.  There are tools that *help* you build a normalized set
of relations.  For someone who has normalized many, many relations, it is hard
to avoid building normalized relations by instinct.  By "tools" I
mean CASE modeling tools such as Excelerator, the Iconix stuff, and
SilverRun LDM and ERM.  Also, IDE for Unix.

But, it sounds like you want something that will do the actual normalization.
There are algorithms for this (See Ullman, again) but I cannot recommend them.

1.  You still must determine all of the functional dependencies by hand.  The
FD's are *business policy*, not computer technology.

2.  They are computationally burdensome.

3.  They sometimes find counter-intuitive relations.

4.  The user/analyst/developer loses a great opportunity to become really
familiar with the contents of the database.