Consider a database relation Employee (SSN, Name). What is the highest normal…

Concept

Normal forms form a strict hierarchy 1NF ⊆ 2NF ⊆ 3NF ⊆ BCNF, where each form adds a stronger constraint on functional dependencies. BCNF is the strongest of these: a relation is in BCNF when, for every non-trivial functional dependency X → Y, the determinant X is a superkey (a candidate key or a superset of one). The "highest normal form" of a relation is the strictest form in this chain that it satisfies.

Application

1. List the attributes and the key. The relation has exactly two attributes, SSN and Name, and SSN uniquely identifies each row, so SSN is the only candidate key.

2. Write the non-trivial functional dependencies. The single non-trivial dependency is SSN → Name.

3. Test the BCNF rule on each dependency. For SSN → Name, the determinant SSN is a candidate key, hence a superkey, so the only dependency already satisfies the BCNF condition.

Cross-check

This matches the general theorem that any relation with only two attributes is automatically in BCNF: the left side of every non-trivial dependency must be one of the two attributes, and in a valid relation that attribute is a superkey. With no partial dependency (single-attribute key) and no transitive dependency (Name depends directly on the key), 2NF and 3NF also hold, but BCNF is the strictest form reached.

Result: the highest normal form satisfied by Employee(SSN, Name) is BCNF.