Functional dependency

Functional Dependency describes the relationship between attributes in a relation. If A and B are attributes of a relation R, B is functionally dependent on A if each value of A is associated with exactly one value of B

Determinant:

Any attribute whose value determines other values within a row. The determinant of a functional dependency refers to the attribute or group of attributes on the left hand side of the arrow.

• If an attribute is determined by only part of the primary key ( the determine A), there is a partial dependency.
• If an attribute is determined by the whole primary key ( the determinate A) there is a full functional dependency.