A Simple Analysis?

From: Randy Yates <yates_at_207.87.184.178>
Date: 2000/05/27
Message-ID: <392F5DF5.94A32B2A_at_207.87.184.178>#1/1

Forgive me if this is a trivial question.

Assume the following example relations represent "all-time" relvar dependencies.

Case 1

---

A B C
0 0 0
0 1 1
1 0 1
1 1 0

This appears to be fully normalized.

Case 2

---

A B C
0 0 0
0 1 1
1 0 0
1 1 1

Not normalized: C is dependent only on B.

Case 3

---

A B C
0 0 0
0 1 1
1 0 2
1 1 2

??? Here it appears that A partitions all the possible values for C. What kind of dependency is here and how (if at all) should it be decomposed?

-- 
% Randy Yates                   % "I met someone who looks alot like you,
%% DIGITAL SOUND LABS           %             she does the things you do, 
%%% Digital Audio Sig. Proc.    %                     but she is an IBM."
%%%% <yates_at_ieee.org>           %        'Yours Truly, 2095', *Time*, ELO   
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Received on Sat May 27 2000 - 00:00:00 CEST