Research of reduct algorithm based on functional dependency

In real application of relation databases, schema of database is pre-defined, of which is not made the best sufficiently in methods to mine rules from database. This paper starts from the new theory to mine classification rules - rough set theory, and create the relationship between the core concept in rough set theory - dispensable property of attributes and the core concept in database schema - functional dependence. Based on the relationship, reducts in rough set theory can be seen as the minimal attribute set that does not contain any functional dependence. We also present the algorithm to retrieve reduct, and prove the correctness.