Suppose R1(A, B) and R2(C, D) are two relation schemas. Let r1 and r2 be the corresponding relation instances. B is a foreign key that refers to C in R2. If data in r1 and r2 satisfy referential integrity constraints, which of the following is ALWAYS TRUE?
(A) B(r1) C(r2) =
(B) C(r2) B(r1) =
(C) B(r1) = C(r2)
(D) B(r1) C(r2) ≠
Rewards per monthFirst Winner: 0 INR (Not Started)Second Winner: 0 INR (Not Started)
Show your Support. Become a FAN!