DATA NORMALIZATION METHOD - Database Design and Development: An Essential Guide for IT Professionals - page 305

form. The process continues through a reasonable number of steps until the result-
ing data model becomes truly relational.
Steps and Tasks
The first few steps of the normalization methodology transform the initial data
model into a workable relational data model that is free from the common types of
irregularities. These first steps produce the normal forms of relations that are fun-
damental to creating a good relational data model. After these initial steps, in some
cases, further irregularities still exist. When you remove the additional irregulari-
ties, the resulting relations become higher normal form relations.
We will discuss the fundamental and higher normal forms in the next section.
However, let us just list the steps here:
Fundamental normal forms
Step 1
Examine initial data model and remove first type of irregularity.
Data model becomes a set of first normal form relations.
Step 2
Inspect data model resulting from previous step and remove second type of
irregularity.
Data model becomes a set of second normal form relations.
Step 3
Inspect data model resulting from previous step and remove third type of
irregularity.
Data model becomes a set of third normal form relations.
Step 4
Inspect resulting data model and remove another type of irregularity.
Data model becomes a set of Boyce-Codd normal form relations.
Higher normal forms
Step 1
Examine data model in the final fundamental normal form and remove fourth
type of irregularity.
Data model becomes a set of fourth normal form relations.
Step 2
Inspect data model resulting from previous step and remove fifth type of irreg-
ularity.
Data model becomes a set of fifth normal form relations.
Step 3
Inspect data model resulting from previous step and remove domain-key
irregularity.
Data model becomes a set of domain-key normal form relations.