DBI202Xuất hiện trong 1 đề thi
The relation $R(A,B,C,D)$ has following FDs: $ACD \to B$; $AC \to D$; $D \to C$; $AC \to B$. Choose the correct statement about $R$:
Các lựa chọn
A$R$ is in 3NF
B$R$ is in 2NF only, not higher
C$R$ is in 1NF only, not higher
DNone of the others