Question

For each of the following relations, indicate the normal form for that relation. If the relation is not in third normal form, decompose it into 3NF relations. Functional dependencies (other than those implied by the primary key) are shown where appropriate.

a. CLASS(CourseNo, SectionNo)
b. CLASS(CourseNo, SectionNo, Room)
c. CLASS(CourseNo, SectionNo, Room, Capacity) [FD: Room → Capacity]
d. CLASS(CourseNo, SectionNo, CourseName, Room, Capacity) [FD: CourseNo→ CourseName; FD: Room → Capacity]

Answer 1

The given relations are already in third normal form (3NF) or can be decomposed into 3NF relations.

Step-by-step explanation:

For each of the given relations:

1. a. CLASS(CourseNo, SectionNo) - This relation is already in third normal form (3NF) because it does not have any non-key attributes or functional dependencies.
2. b. CLASS(CourseNo, SectionNo, Room) - This relation is also in 3NF because it does not have any non-key attributes or functional dependencies.
3. c. CLASS(CourseNo, SectionNo, Room, Capacity) [FD: Room → Capacity] - This relation is also in 3NF because it does not have any non-key attributes or functional dependencies other than the implied dependency between Room and Capacity.
4. d. CLASS(CourseNo, SectionNo, CourseName, Room, Capacity) [FD: CourseNo → CourseName; FD: Room → Capacity] - This relation is not in 3NF because it has a non-key attribute CourseName that depends on a partial key (CourseNo). To decompose it into 3NF relations:
5. CLASS1(CourseNo, CourseName)
6. CLASS2(CourseNo, SectionNo, Room, Capacity)