Advanced Normalization Topics

Abstract

If it has been said once, it has been said a million times: “This database is in the Third Normal Form, and that is good enough!” In this chapter, you’ll look at one additional very important method for normalization, and you’ll be introduced to a few others. The additional methods of normalization aren’t commonly used because of perceived drawbacks in terms of both the time taken to implement them, and the cost in performance of the resulting database. In the previous chapter, you looked at some of the different programming anomalies that the Third Normal Form deals with, but as you’ll see, there may still be some problems remaining in your logical design, mostly caused by the presence of nonbinary relationships. In essence, while most people think they have completed the normalization process after having reached the Third Normal Form, what they really should be concerned with is at least reaching the Third Normal Form in their logical model. A degree of judgment is required in physically implementing a design and determining what level of normalization is appropriate. However, as a general guide, the designer should always attempt to normalize all entities to as high a form as possible.