Database Reference
In-Depth Information
technology, but that path has been set as the next leap in the com-
puter revolution. Oracle Corporation is pursuing a grid approach and
has always been visionary in the past.
Now let's look at the basics of relational data modeling, which is impor-
tant because SQL is based on and stems from the relational data model.
1.2
The Basics of Relational Data Modeling
1.2.1
Normalization
1,2,3
Normalization
is a process of removal of duplicated information.
Removal of duplication reduces the space used and enforces a logical struc-
ture. Relational data modeling utilizes a process called Normalization using
what are called Normal Forms. The three most commonly used Normal
Forms or NF are called 1NF, 2NF, and 3NF. There are other subsidiary and
often overly detailed Normal Forms called 4NF, 5NF, and even beyond
those. I always thought of the accepted definitions of the different Normal
Forms as being academic and far too complex to make any sense of, unless
they are read about five times each. Therefore, I like to simplify the explana-
tions of Normal Forms as follows:
Figure 1.8
First Normal Form
(1NF).
