Partial+Dependency+Definition

If an attribute is not dependent on **all** of the keys in the relation, we say that it has partial dependency on the key.

For example, look at the relation below:

The relation has 2 keys - the primary key **pupil_id** and the foreign key **course_id**.

The attributes **pupil_name**, **dob** and **tutor_group** rely only on the primary key of **pupil_id**. They do not rely on the foreign key course_id. These 3 attributes are partially dependent on the primary key.

In order to show a relation in 2NF, all partial dependencies must be removed.