Q1. Recent changes in the privacy laws encompass disallowed organizations from using SSN to recognize individuals unless certain restrictions are satisfied. As an outcome, most US universities can’t use SSN as primary key (apart from for financial data). In practice, StudentID, a unique ID, a unique identifier, assigned to every student, is probable to be used as the primary key instead of SSN as StudentID is usable across all aspects of the system.
a) Some of the database designers are reluctant to use generated keys (as well named as surrogate keys) as primary keys (like StudentID) as they are artificial.
Can you recommend any natural choices of keys which can be used to store the student record in a UNIVERSITY database?
b) Assume that you were able to guarantee uniqueness of a natural key that comprised last name. Are you guaranteed that the last name will not change throughout the lifetime of the database? If the last name can change, what solutions can you suggest for making a primary key which still comprises last name however remains unique?
Q2. Explain the conditions where each of the different isolation levels would be helpful for transaction processing.