Finding Candidate Keys | Class Practice | Unacademy

Question

Find the candidate key(s) of the relation R(UVWXYZ) with FD set F={UV-->W, XW-->Y, U-->XZ, Y-->U}

• A. XW
• B. UV, YV, WXV
• C. YUV, XV, WV
• D. None of these

Comments

$A)$ $\{X,W\}^+ =\{X,W,Y,U,Z\}$ ($V$ is not here)

$B)$ $\{U,V\}^+ =\{U,V,W,X,Z,Y\}$

$\{Y,V\}^+ = \{Y,V,U,X,Z,W\}$

$\{W,X,V\}^+ = \{W,X,V,Y,U,Z\}$

$C) \{X,V\}^+ =\{X,V\}$ ($U,W,Y,Z$ are not here)

Hence, $B$