State two conditions that indicate when a database designer should consider using supertype/subtype relationships. 

 

State the reason for entity clustering. 

 

Give an example (other than those discussed in the chapter) of a supertype/subtype relationship. 

 

What is attribute inheritance? Why is it important? 

 

Give an example of each of the following: 

 

supertype/ subtype relationship where the disjoint rule applies 

 

supertype/subtype relationship where the overlap rule applies 

 

What types of business rules are normally captured in an EER diagram? 

 

What is the purpose of a subtype discriminator? 

 

When would a packaged data model be useful? 

 

When might a supertype/ subtype hierarchy be useful? 

 

When is a member of a supertype always a member of at least one subtype?