Transitive Functional Dependency (Databases)

A transitive functional dependency is a FD $X\to Y$ that can be derived from two other FDs: $X\to Z$ and $Z\to Y$.

Examples:

• $\text{SSN}\to \text{DMGRSSN}$ is a transitive FD as SSN into DNUMBER and DNUMBER into DMGRSSN both hold.
• $\text{SSN}\to \text{ENAME}$ is non-transitive since there is no set of attributes $X$ where $\text{SSN}\to X$ and $X\to \text{ENAME}$.