Relation R(A,B,C,D) has functional dependencies: $A \rightarrow B$, $BC \rightarrow D$, $D \rightarrow A$. Determine the number of candidate keys of R. Then, if R is decomposed into R1(A,B) and R2(B,C,D), state whether the decomposition is lossless‑join.

Question

Accepted Answer

2 candidate keys; the decomposition is not lossless‑join.

Neco 2021 Data Processing Question 1

Relation R(A,B,C,D) has functional dependencies: \(A \rightarrow B\), \(BC \rightarrow D\), \(D \rightarrow A\). Determine the number of candidate keys of R. Then, if R is decomposed into R1(A,B) and R2(B,C,D), state whether the decomposition is lossless‑join.

Answer Options

About This Question

Master the Exam!