Definition: A trivial functional dependency occurs when you describe a functional dependency of an attribute on a collection of attributes that includes the original attribute. This type of functional dependency is called trivial because it can be derived from common sense. It is obvious that if you already know the value of B, then the value of B can be uniquely determined by that knowledge.
For more detail, read What is a Database Dependency?
For more detail, read What is a Database Dependency?
Examples:
For example, “{A, B} -> B” is a trivial functional dependency, as is “{name, SSN} -> SSN”.
