Question

A(n) ________ exists when there are functional dependencies such that Y is functionally dependent on X,Z is functionally dependent on Y, and X is the primary key.

a. partial dependency
b. repeating group
c. atomic attribute
d. transitive dependency

Answer 1

A transitive dependency exists when one non-primary-key attribute is dependent on another non-primary-key attribute, which is itself dependent on the primary key. It indicates that the database is not in Third Normal Form and requires normalization to eliminate this dependency.

Step-by-step explanation:

The situation described involves a transitive dependency. In database normalization, a transitive dependency occurs when there is a set of functional dependencies in a database such that one non-primary-key attribute, Z, is functionally dependent on another non-primary-key attribute, Y, which is itself functionally dependent on the primary key, X. This typically indicates that the database schema is not in Third Normal Form (3NF), which requires that there are no transitive dependencies involving non-prime attributes (attributes not part of a candidate key). To resolve this, normalization typically involves decomposing the table structures to eliminate the transitive dependency and to enforce that each non-key attribute is only dependent on the primary key.