Question

Which functional dependency does not holds in given relation and why?

Q: Answer-Which functional dependency does not holds in given relation and why?

v-wx satisfies condition 3 i.e. value of v is repeated 3 times 7 then value of wx is also repeated . so option 1 is correct. yz-x satisfies condition 2, i.e. all values of x are same, so option 2 is correct. x -yz does not satisfy any of the three conditions, so option 3 is incorrect.

Read the below passage and answer the questions Functional dependency A B means that B is dependent on A
i.e. from the value of A we can find the value of B from the relation. Therefore, to prove A B holds in a relation, one of the following conditions must be true: Condition1: either all the value of A must be unique Or Condition2: all the value of B must be same Or Condition3: If two or more tuples/rows of the relation have same value for attribute A then there must be also same value for attribute B
i.e. if t1[A] = t2[A] then there must be t1[B] = t2[B].

A 1

B 2

C 3

D None of these

E All of these

Practice Next