DBI202Xuất hiện trong 1 đề thi
Consider a relation $R(A,B,C,D)$ with functional dependencies: $A \to C$, $AB \to A$, $A \to CB$, $AD \to ABC$. Which of the following is a trivial functional dependency of the relation?
Các lựa chọn
A$AB \to A$
B$AD \to ABC$
C$C \to CB$
D$AB \to A$, $C \to CB$