Data Normalization - Information Systems Reengineering, Integration and Normalization - page 369

systems reengineering is more than the cost of database reengineering. The former
is on the application aspect, and the latter is on the implementation aspect.
Similarly, data normalization and data denormalization are two aspects of meet-
ing users data requirements. If the users ask for user friendliness in database ma-
nipulation, then data normalization is recommended. However, if the users ask for
better performance in information retrieval such as data warehousing, then data
denormalization is recommended. Very often, the normalized relations can be de-
normalized by performing natural join operations together to recover the original
relation before data normalization in relational database.
Questions
Question 9.1
a. What are the preconditions to perform normalization for the 4NF and the 5NF in
terms of N-ary relationship.
b. Illustrate the answer of (a) with examples by using an Entity-Relationship (ER)
Model before and after normalization.
c. Derive the first, second, and third normal form for the following UNF includ-
ing 11 data fields with 5 of them are in repeating groups in a table. Identify the
functional dependencies of each normal form.