Consider the relation R A B C D E F G H A rightarrow B C D

Consider the relation R = {A, B, C, D, E, F, G, H}. {A} rightarrow {B, C, D, F, G}, {B} - > {C, D}, and {E} rightarrow {G, H} are functional dependencies defined on r. What is the key of R? Normalize R. R will be decomposed into relations (tables).

Solution

AE is the key of the relation R.

If we find closure set of AE only we can cover all the attributes.

As the given 3 tables are in 2NF we have to remove Trivial dependencies.

So,

A->B,F (B as a foreign key to next table.)

B->C,D

E->H

AE->G (As their is a trivial dependency of attribute G, we removed it to a seperate table, with a candidate key AE to that table)