Question 3248 – Communication
March 26, 2024Database-Management-System
March 26, 2024Database-Management-System
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Question 240
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Let R = (A, B, C, D, E) having following FD’s.
F = {A → BC, CD → E, B → D, E → A}
Which of the following is not a Candidate key?
F = {A → BC, CD → E, B → D, E → A}
Which of the following is not a Candidate key?
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A
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B
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E
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BC
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Question 240 Explanation:
Closure(A)+ = { A, B, C, D, E }
Closure(B)+ = { B, D }
Closure(E)+ = { A, B, C, D, E }
Closure(BC)+ = { A, B, C, D, E }
Closure(B)+ = { B, D }
Closure(E)+ = { A, B, C, D, E }
Closure(BC)+ = { A, B, C, D, E }
Correct Answer: B
Question 240 Explanation:
Closure(A)+ = { A, B, C, D, E }
Closure(B)+ = { B, D }
Closure(E)+ = { A, B, C, D, E }
Closure(BC)+ = { A, B, C, D, E }
Closure(B)+ = { B, D }
Closure(E)+ = { A, B, C, D, E }
Closure(BC)+ = { A, B, C, D, E }