Assignment 1 Semester 2 2025
Unique Number:
Due Date: 28 August 2025
QUESTION 1
a. When a 3rd NF relation is in BCNF and when it is not
A relation is in 3rd Normal Form (3NF) if every non-prime attribute is fully functionally
dependent on the primary key and there are no transitive dependencies.
A relation is in Boyce-Codd Normal Form (BCNF) if, for every functional dependency (X →
Y), the determinant X is a superkey.
3NF but not BCNF:
This happens when a non-prime attribute depends on part of a candidate key.
Example: Suppose we have a relation Course(Instructor, CourseCode, Room), with
dependencies:
Instructor → Room
CourseCode → Instructor
Here, the table is in 3NF (since all non-key attributes depend on candidate keys) but not in
Terms of use
BCNF because Instructor is not a superkey, yet it determines Room.
By making use of this document you agree to:
Use this document as a guide for learning, comparison and reference purpose,
Terms of use
Not to duplicate, reproduce and/or misrepresent the contents of this document as your own work,
By making use of this document you agree to:
Use this document
Fully accept the consequences
solely as a guide forshould you plagiarise
learning, reference,or and
misuse this document.
comparison purposes,
Ensure originality of your own work, and fully accept the consequences should you plagiarise or misuse this document.
Comply with all relevant standards, guidelines, regulations, and legislation governing academic and written work.
Disclaimer
Great care has been taken in the preparation of this document; however, the contents are provided "as is" without any express or
implied representations or warranties. The author accepts no responsibility or liability for any actions taken based on the
information contained within this document. This document is intended solely for comparison, research, and reference purposes.
Reproduction, resale, or transmission of any part of this document, in any form or by any means, is strictly prohibited.