Problem 4 Consider the relational schema FOOW X Y Z that ha

Problem 4 - Consider the relational schema FOO(W, X, Y, Z) that has {W, X} as the
primary key (same as the previous problem). Now, develop a set of functional dependencies (FDs)
under which FOO does not violate 2NF but does violate 3NF. Explain your answer and remember
that your set of FDs must support the provided primary key.

Solution

FOO (W, X, Y, Z)

Primary Key is {W, X}

Dependencies are

WX->YZ

W->Y

Here W->Y breaks 2NF as according to 2NF partial need should not be permitted. Here WX is main key so that W is prime attribute. Y, Z is non prime attribute. Prime attribute cannot follow non prime attribute. Thus FOO violate 2NF.