Database Systems 6th Edition by Ramez Elmasri, Shamkant B. Navathe

Exercise 4

Recent changes in privacy laws have disallowed organizations from using SSN to identify individuals unless certain restrictions are satisfied. As a result, most US universities cannot use SSNs as primary keys (except for financial data). In practice, StudentID, a unique ID, a unique identifier, assigned to every student, is likely to be used as the primary key rather than SSN since StudentID is usable across all aspects of the system.
a. Some database designers are reluctant to use generated keys (also known as surrogate keys) for primary keys (such as StudentID) because they are artificial. Can you propose any natural choices of keys that can be used to store the student record in a UNIVERSITY database?
b. Suppose that you were able to guarantee uniqueness of a natural key that included last name. Are you guaranteed that the last name will not change during the lifetime of the database?
If the last name last name can change, what solutions can you propose for creating a primary key that still includes last name but remains unique?
c. What are the advantages and disadvantages of using generated (surrogate) keys?