What is BCNF?

Boyce-Codd Normal Form (BCNF) is a stronger normalization condition than 3NF. Informally, for every non-trivial functional dependency X → Y in a relation, X should be a superkey.

Most routine application schemas focus on 1NF through 3NF, but BCNF becomes relevant when a table has overlapping candidate keys or dependency structures that can still produce anomalies even though the table appears to satisfy 3NF.