4. (40 points) Identify the following relations that are in Third normal form (3NF)? If it is in 3NF, is it in BCNF? You must explain your answer to receive points. Also, for each question, pick one FD not in BCNF and decompose R into tables if it is not in BCNF. (2) R(ABCD) FD’s: AB-»C; ABD->C; ABC-> D; AC-ID (4) R(ABCD) FD’s: C- B;A->B; CD -»A; BCD (5) R(ABCD) FD’s: AD
OR
OR