DBI202Xuất hiện trong 1 đề thi
Consider the relation $R(A,B,C,D)$ and functional dependencies: $AB \to CB$, $C \to AD$, $A \to C$. Which set of functional dependencies is equivalent to the original set?
Các lựa chọn
A$AB \to C$, $C \to A$, $C \to D$, $A \to C$
B$A \to C$, $C \to D$
C$AB \to D$
D$AB \to CBD$
E$AB \to C$, $C \to A$, $C \to D$, $A \to C$, $CD \to A$