DATA NORMALIZATION METHOD - Database Design and Development: An Essential Guide for IT Professionals - page 322

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Figure 10-17 University information: final relational data model.

irregularities resulting from incorrect functional dependencies in the original
relations.
• In practice, after the initial data model goes through the first four steps for fun-
damental normal forms, the resultant data model becomes truly relational and
suitable for completing the logical design. No further normalization steps are
usually necessary.
• The next three steps remove irregularities resulting from other types of incor-
rect dependencies in the original relations. These steps transform the data
model into higher normal forms.
• The normalization method of creating a relational data model is difficult when
the real-world information you are trying to model is large and complex.

REVIEW QUESTIONS

1. “The method of creating a relational data model seems to be an informal
design technique.” Discuss briefly.
2. Describe briefly the process of creating an initial data model from real-world
information requirements. Why is this initial data model potentially incor-
rect?
3. “An update anomaly occurs when values of attributes are updated in a data-
base.” Explain with an example.