of the relations not in BCNE? Solution: a)key:HS b)implied FD's:CH→R,TH今C,HR今T,CTH→R,. c)They are the minimal basis.Because Right sides are single attributes.No FD can be removed.No attribute can be removed from a left side. d)According to 3NF synthesis,the relation is decomposed into R1(CT),R2 (HRC),R3(HTR),R4(HSR),R5(CSG)they are also in BCNF. Exercise 3.6.3 a),c) a)R(A,B,C,D)with MVD'sA→→B,A→→C c)A relation R(A,B,C,D)with MVD AB→→C,and FD B→D O Find all the 4NF violations Decompose the relations into a collection of relation schemas in 4NF Find the keys of the relation based on FD's a)Solutions:of the relations not in BCNF? Solution: a) key: HS b) implied FD’s: CHR, THC, HRT,CTHR,… c) They are the minimal basis. Because Right sides are single attributes. No FD can be removed.No attribute can be removed from a left side. d) According to 3NF synthesis, the relation is decomposed into R1(CT),R2(HRC),R3(HTR),R4(HSR),R5(CSG) they are also in BCNF. Exercise 3.6.3 a), c) a) R(A,B,C,D) with MVD’ s AB, AC c) A relation R(A,B,C,D) with MVD ABC, and FD BD  Find all the 4NF violations  Decompose the relations into a collection of relation schemas in 4NF  Find the keys of the relation based on FD’s a) Solutions: