UGC-NET | UGC NET CS 2014 Dec – II | Question 20

Identify the minimal key for relational scheme R(A, B, C, D, E) with functional dependencies F = {A → B, B → C, AC → D}
(A) A
(B) AE
(C) BE
(D) CE

Answer: (B)
Explanation: A⁺ = ABCD
But we can’t derive E from A, so We have to add E i A
I.e. AE⁺ = ABCDE.
So, option (B) is correct.
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