Deductive Database:
A deductive database system is a database system which can make deductions (ie: infer additional rules or facts) based on rules and facts stored in the (deductive) database.Deductive database systems:* Mainly deal with rules and facts.* Use a declarative language (such as prolog) to specify those rules and facts.* Use an inference engine which can deduce new facts and rules from those given.
From:en.wikipedia.org/wiki/Deductive_database