Question 1. What is denormalization, and why can it be desirable? Provide an example.
Question 2. Give examples of binary 1:N relationships, (a) an optional-to-optional relationship, (b) an optional-to-mandatory relationship, (c) a mandatory-to-optional relationship, and (d) a mandatory-to-mandatory relationship. Illustrate using IE Crow's Foot E-R diagrams.