Question - What do you understand by functional dependency and transitive dependency in DBMS?
Answer -
Functional Dependency: A functional dependency is a constraint that is used in describing the relationship among different attributes in a relation.
Example: Consider a relation “A1” having attributes X and Y. The functional dependency among these two attributes will be X -> Y, this implies that Y is functionally dependent on X.
Transitive Dependency: A transitive dependency is a constraint that can only occur in a relation of three or more attributes.
Example: Consider a relation “A1” having attributes X, Y and Z. Now, X->Z is said to hold transitive dependency, only if the following functional dependencies holds true:
- X -> Y
- Y doesn’t ->X
- Y -> Z