Problem

When designing an E-R diagram for a particular enterprise, you have several alternatives from which to choose.

a. What criteria should you consider in making the appropriate choice?

b. Design three alternative E-R diagrams to represent the university registrar's office of Exercise 2.4. List the merits of each. Argue in favor of one of the alternatives.

Exercise 2.4

A university registrar's office maintains data about the following entities:

(a) courses, including number, title, credits, syllabus, and prerequisites;

(b) course offerings, including course number, year, semester, section number, instructor(s), timings, and classroom;

(c) students, including student-id, name, and program; and

(d) instructors, including identification number, name, department, and title. Further, the enrollment of students in courses and grades awarded to students in each course they are enrolled for must be appropriately modeled. Construct an E-R diagram for the registrar's office. Document all assumptions that you make about the mapping constraints.