GATE | GATE CS 2021 | Set 2 | Question 50
Suppose the following functional dependencies hold on a relation U with attributes P,Q,R,S, and T:
P → QR RS → T
Which of the following functional dependencies can be inferred from the above functional dependencies?
(A) PS → T
(B) R → T
(C) P → R
(D) PS → Q
Answer: (A) (C) (D)
P-> QR RS-> T
From P->QR we derived P->Q and P->R.
After getting R from P we derive PS->T .
We directly derive Q from P so PS->Q also holds true.
Correct Option A , C, D