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INFO210_HW4_solution

# A suppose that the following fds hold ina r ry

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Unformatted text preview: 1 b1 c1 d1 e1 a2 b2 c1 d1 e1 a3 b3 c2 d2 e2 a4 b1 c3 d3 e2 D - > E E - > D BC - > C Solution: D - > E (yes) E - > D (no, tuples 3 and 4 violate this) BC - > C (yes, this is a trivial dependency) Problem 2 (15pts) Consider relation Professor (id, name, address, rank, years_in_rank, salary), denoted INARYS for brevity. Suppose that id is the only candidate key of this relation. (a) Suppose that the following FDs hold: INA - > R, RY - > S Is Professor in BCNF? Explain you answer. If your answer is no, clearly identify all FDs that violate BCNF. Solution: No, Professor is not in BCNF. The FD RY - > S violates BCNF, since RY is not a key or a superkey for this relation, and this is not a trivial FD. (b) Suppose th...
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