Functional Dependency (FD)

• Given:

  • r(R): a relation
  • A: a set of attributes in r(R)
  • B: a set of attributes in r(R)

• A → B: iff for any tuples t1 and t2 t1(B)=t2(B) where t1(A)=t2(A).

• A → B is a functional dependency (FD)