this is design database class, please help
(4) (30%) (a) R(A,B,C,D) has two candidate keys and A is one of them. What are the range of superkeys R may have? (b)List the highest normal forms for the following relations [i] R(A,B,C,D) {A->D, B->C) [ii] R(A,B,C,D) A->D, B->CD) [ii] R(A,B,C,D) A->D, D->B) [iv] R(A,B,C,D) A->D, D->BC) [] R(A,B,C,D) A->D, D->ABC) (c) It is known that for R(A,B,C,D): 1. R has exactly 4 superkeys. 2.
OR
OR