Why bcnf is gretter than 3nf?

BCNF (Boyce-Codd Normal Form) is considered greater than 3NF (Third Normal Form) because it addresses certain types of redundancy that 3NF does not eliminate. Specifically, BCNF requires that every determinant in a functional dependency is a candidate key, thus ensuring that all non-trivial functional dependencies depend on the whole key. This means BCNF can better prevent update anomalies and maintain data integrity in more complex database designs. As a result, databases in BCNF tend to be more optimized for performance and consistency.