INF2603 Assignment 5 2025 (865742) Due 5 September 2025.

INF2603
Assignment 5
Unique No: 865742
Due 5 September 2025

, INF2603

Assignment 5: 865742

Due 5 September 2025



Database Design and SQL


1. Situations When a 3rd Normal Form (3NF) Relation is in BCNF and When It Is
Not



When a 3NF Relation Is Also in BCNF:


A relation that satisfies 3NF is also in BCNF if every functional
dependency has a candidate key on its left-hand side. This condition
ensures that no non-trivial dependency violates the key principle of
BCNF.
Example:


STUDENT(StudentID → Name, StudentID → Email)

StudentID is the candidate key.

All functional dependencies have the candidate key as their
determinant.

This relation satisfies both 3NF and BCNF.


When a 3NF Relation Is Not in BCNF:

A relation in 3NF may fail to meet BCNF conditions when a non-prime
attribute (not part of any candidate key) serves as a determinant.
Example:

COURSE(CourseID, Lecturer, Room)