dependency

Question

R(ABCDEF) and functional dependency set F={AB->CDEF , F->C , C->A , B->D, D->E,F->B}

candidate keys are F , AB and BC

which are partial dependencies to be removed to obtain 2NF

Answer 1

$B\longrightarrow D\space and\space D\longrightarrow E$ 

Because F,AB,BC is given as Candidate key

In Second Normal Form All Non Prime Attribute should be Fully Functional Dependent on any key

So NPA=D,E

$AB\longrightarrow CDEF$

(NPA is FFD on Key AB so 2NF)

, $F\longrightarrow C$  (2NF)

, $C\longrightarrow A$ (2NF)

, $B\longrightarrow D$ ,

(D is NPA but B is not key so not 2NF)

,$D\longrightarrow E$

(E is NPA but D is not Key so not 2NF)

,$F\longrightarrow B$

Comments

yea which means it shouldnt have partial dependency

D->E is not having partial dependency right

because both are not prime attributes

My doubt is if C->A is violating 2NF?

because C is part of BC

and if its not then what is the reason?

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No C and A is not NPA so 2NF