Transitive dependency is a functional dependency which holds by virtue of transitivity. A transitive dependency can occur only in a relation that has three or more attributes. Let A, B, and C designate three distinct attributes (or distinct collections of attributes) in the relation.
Suppose all three of the following conditions hold:
A -> B
It is not the case that B ? A
B ->C
Then the functional dependency A -> C (which follows from 1 and 3 by the axiom of transitivity) is a transitive dependency.
