ER-Model

Question 5

In a schema with attributes A, B, C, D and E following set of functional dependencies are given

A → B 
A → C 
CD → E 
B → D 
E → A

Which of the following functional dependencies is NOT implied by the above set?

Question 5 Explanation:

Apply membership test for all the functional dependencies.
Option (B):
BD → CD
BD⁺ = BD
i.e., BD cannot derive CD and hence is not implied.

Correct Answer: B

Question 5 Explanation:

Apply membership test for all the functional dependencies.
Option (B):
BD → CD
BD⁺ = BD
i.e., BD cannot derive CD and hence is not implied.