Which normal form eliminates partial dependency of non-key attributes on the primary key?

• A. 1NF
• B. 2NF
• C. 3NF
• D. BCNF

Answer: (B)

Partial dependency happens when a non-prime attribute depends on only part of a composite primary key. Second Normal Form removes these by requiring that every non-prime attribute be fully functionally dependent on every candidate key. In other words, if the primary key is made of multiple attributes, no non-key attribute should depend on just one part of that key. When such a dependency exists, you decompose the table so that the dependent attribute moves to its own relation tied to the relevant key part. This is why the best answer is Second Normal Form: it specifically targets and eliminates partial dependencies. For context, 1NF deals with atomic values, 3NF removes transitive dependencies, and BCNF tightens that further by requiring every determinant to be a candidate key.