Boyce-Codd Normal Form

relational-algebra

Definition

Boyce-Codd Normal Form

A schema $\mathcal{R}$ is in Boyce-Codd normal form if for every functional dependency $\alpha \to B$ with attribute $B\in \mathcal{R}$, at least one of the following two conditions holds:

1. $B\in \alpha$, i.e. the functional dependency is trivial
2. $\alpha$ is super key of $R$

The BCNF is a more restrict version of the 3NF.