BCS 260 Lecture Notes - Functional Dependency, Candidate Key, International Standard Book Number
Document Summary
These rules are useful for figuring out candidate keys and working with fds: if you have a b and you have b c, then you also have. A bc: if you have a bc then and you have a b and you also have. Ac: for any attribute c, if you have a b then ac bc. In sum, functional dependency and determinant means a functional dependency is a logical relationship in which the value of one item in the relationship can be determined by knowing the value of the other item. Examples: isbn book title area = length * width, the functional dependency is (length, width) area (length, width) is the determinant. Length and width are determinants because we need both. A (b, c) means that a value of a determines the value of both b and c. we can say that a b and a c.
