15. Break up the dependency diagram you drew in problem 14 to produce dependency diagrams that are in 3NF. (Hint: You may have to create a few new attributes. Also, make sure that the new dependency diagrams contain attributes that meet proper design criteria; that is, make sure that there are no multi-valued attributes, that the naming conventions are met, and so on.)

 

Dependency diagrams have no way to indicate multi-valued attributes, nor do they provide the means through which such attributes can be handled. Therefore, the solution to this problem requires a basic knowledge of modeling concepts, once again indicating that normalization and design are part of the same process. Given the sample data shown in Problem 14, EDUCATION, DEPENDENTS and TRAINING are multi-valued attributes whose values are stored as strings. We have created the appropriate entities to avoid the use of multi-valued attributes. (See Figure P5.15.)

 

Figure P5.15  The Dependency Diagrams for Problem 15