Question

Identify what you think should be candidate keys, and write in your own words the constraints under which each candidate key would be valid.

Answer 1

Solution:-

Identify what you think should be candidate keys, and write in your own words the constraints under which each candidate key would be valid:-

Any relation schema may have more than one key. In this case, each of the keys is called a candidate key. It is common to designate one of the candidate keys as the primary key of the relation. This is the candidate key whose values are used to identify tuples in the relation. All possible candidate keys include the following:

1. (Univ_Section#) - If it is unique across all semesters.
2. (Semester, BuildingCode, Room#, TimePeriod, Weekdays) - If more than one course cannot be conducted in the same room during a particular semester.
3. (InstructorName, Semester) - If an instructor can only teach one course in each semester.
4. (Course#, Univ_Section#, Semester) - would be the candidate key, If (Univ_Section#) is not unique across all semesters.