Deductive database

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A deductive database system is a database system which can make deductions (ie: infer additional rules or facts) based on 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.

A good example of a declarative language would be prolog, but for databases “datalog” is used more often. Datalog is both a syntactic subset of prolog and a database query language – it is designed specifically for working with logic and databases. Deductive databases are also known as: logic databases, knowledge systems and inferential databases. The problem domain of an expert system / deductive database is usually quite narrow. Deductive databases are similar to expert systems - “traditional” expert systems have assumed that all the facts and rules they need (their knowledge base) will be loaded into main memory, whereas a deductive database uses a database (usually on disk storage) as its knowledge base. Traditional expert systems have usually also taken their facts and rules from a real expert in their problem domain, whereas deductive databases find their knowledge inherent in the data. Deductive databases and expert systems are mainly used for:

Replicating the functionality of a real expert.
Hypothesis testing.
Knowledge discovery (finding new relationships between data).

Reference

Author: Elmasri and Navathe Title: Fundamentals of database systems (3rd edition) Publisher: Addison-Wesley Longman ISBN 0-201-54263-3

Deductive database

Reference

See also