2. Exercise 3.5.1 For each of the relation schemas and sets of FDs of Exercise 3.3.1 c) :

c) R(A, B, C, D) with FDs AB --> C, BC --> D, CD --> A, and AD --> B.

i) Indicate all the 3NF violations.

ii) Decompose the relations, as necessary, into collections of relations that are in 3NF.