Assume that we have a relation R(A, B, with tuples (r1, r2, r3), (r4, r2, r3), (r5, r3, r3), and (r5, r3, r4). Which of the following functional dependencies does not hold in R?
A. A → B
B. BC → A
C. B → C
D. B ->-> C
Answer:B
Assume that we have a relation R(A, B, with tuples (r1, r2, r3), (r4, r2, r3), (r5, r3, r3), and (r5, r3, r4). Which of the following functional dependencies does not hold in R?
A. A → B B. BC → A C. B → C D. B ->-> C