Ace Test Series: Databases - Functional Dependencies

Question

Find what FD is violated by the Relation R = { } i.e. empty relation

a. All FD

b. Does not violate FD's

c. Cannot say

d. None of the Above

Comments

Let us take by example,

 let relation be R(A,B) and FD is X -> Y.

Now X can take { ∅, X, Y , XY} and Similarly Y can be { ∅, X, Y , XY}.

For Empty relation R( ), there is at least one FD which is ∅ -> ∅.

Correct me if i am wrong.

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b. Does not violate FD's

//No relation exist.We can have no example to violating it...?

Answer 1

b)does not violate any fd as there are no attributes so it is in Highest normal form possible . Plz correct me if I am wrong

Comments

What's the correct???

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b is correct

Answer 2

.We can have only 1 FD for the empty Relation which determines ∅.

∅ ->∅ . Therefore, it is not violating any FD’s.

Option B is correct.