Which normalization form eliminates partial dependencies?

• A. 1NF eliminates repeating groups.
• B. 2NF eliminates partial dependencies.
• C. 3NF eliminates transitive dependencies.
• D. BCNF eliminates all functional dependencies.

Answer: (B)

Partial dependencies occur when a non-prime attribute depends on only part of a composite key. Second Normal Form targets this exactly: every non-prime attribute must be fully functionally dependent on every candidate key. That means if any attribute depends on just part of a composite key, the relation isn’t in 2NF and should be decomposed so the dependency uses the whole key. By enforcing full dependency on the keys, 2NF removes those partial dependencies from the schema.

First Normal Form only requires atomic attribute values, not the dependency structure. Third Normal Form focuses on removing transitive dependencies, where a non-prime attribute depends on another non-prime attribute rather than directly on the key. Boyce-Codd Normal Form tightens the rule so every determinant is a superkey, but it isn’t described as specifically eliminating partial dependencies.