Question 10427 – Deadlock
February 29, 2024Question 14220 – Probability-and-statistics
February 29, 2024Question 11589 – Functional-Dependency
Let R = (A, B, C, D, E, F) be a relation schema with the following dependencies:
C → F,E → A, EC → D, A → B
Which of the following is a key for R?
Correct Answer: B
Question 18 Explanation:
Let’s find closure of each options,
(CD)+ = CDF X
(EC)+ = ECFDAB ✓
(AE)+ = AEB X
(AC)+ = ACBF X
(CD)+ = CDF X
(EC)+ = ECFDAB ✓
(AE)+ = AEB X
(AC)+ = ACBF X
CD
EC
AE
AC
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