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Issue No. 01 - February (1994 vol. 6)
ISSN: 1041-4347
pp: 96-107
<p>Constraints play an important role in the efficient query evaluation in deductive databases. Constraint-based query evaluation in deductive databases is investigated, with emphasis on linear recursions with function symbols. Constraints are grouped into three classes: rule constraints, integrity constraints, and query constraints. Techniques are developed for the maximal use of different kinds of constraints in rule compilation and query evaluation. The study on the roles of different classes of constraints in set-oriented evaluation of linear recursions shows the following: rule constraints should be integrated with their corresponding deduction rules in the compilation of recursions; integrity constraints, including finiteness constraints and monotonicity constraints, should be used in the analysis of finite evaluability and termination for specific queries; and query constraints, which are often useful in search space reduction and termination, should be transformed, when necessary, and should be pushed into the compiled chains as deeply as possible for efficient evaluation. The constraint-based query-processing technique integrates query-independent compilation and chain-based query evaluation methods and demonstrates its great promise in deductive query evaluation.</p>
deductive databases; query processing; knowledge based systems; program compilers; constraint handling; data integrity; constraint-based query evaluation; deductive databases; linear recursions; function symbols; rule constraints; integrity constraints; query constraints; rule compilation; set-oriented evaluation; deduction rules; finiteness constraints; monotonicity constraints; finite evaluability; search space reduction; compiled chains; chain-based query evaluation methods; query-independent compilation

J. Han, "Constraint-Based Query Evaluation in Deductive Databases," in IEEE Transactions on Knowledge & Data Engineering, vol. 6, no. , pp. 96-107, 1994.
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