Neco 2018 Computer Studies Question 36

Practice objective / multiple choice question 36 from the 2018 Neco Computer Studies examination.

Neco 2018 Computer Studies Objective / Multiple Choice Hard Difficulty
Question 36 NECO • 2018 • COMPUTER_STUDIES • objective

Consider a relation R(A,B,C,D,E) with functional dependencies: \( A \rightarrow B \), \( BC \rightarrow D \), \( D \rightarrow E \), and \( E \rightarrow A \). (a) List all candidate keys of R. (b) Decompose R into Boyce‑Codd Normal Form (BCNF). (c) State whether the decomposition is lossless‑join and whether it preserves all dependencies.

Answer Options

A. Candidate keys: AC, BD, CE. BCNF decomposition: R1(A,B), R3(D,E), R4(A,C,D). Lossless‑join: Yes. Dependency preserving: Yes.
Correct Answer B. Candidate keys: AC, CE, CD. BCNF decomposition: R1(A,B), R3(D,E), R4(A,C,D). Lossless‑join: Yes. Dependency preserving: No.
C. Candidate keys: AC, CE, CD. BCNF decomposition: R1(A,B), R2(B,C), R3(C,D), R4(D,E). Lossless‑join: No. Dependency preserving: No.
D. Candidate keys: AB, AD, CE. BCNF decomposition: R1(A,B), R2(B,C), R3(D,E). Lossless‑join: No. Dependency preserving: Yes.
Correct Answer
B
Correct Option:
Candidate keys: AC, CE, CD. BCNF decomposition: R1(A,B), R3(D,E), R4(A,C,D). Lossless‑join: Yes. Dependency preserving: No.

About This Question

This is Neco 2018 Computer Studies Question 36. It is one of the objective questions from the 2018 Neco Computer Studies examination.

Difficulty level: Hard .

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