We propose a semantic query optimization method in deductive databases using integrity constraints including inclusion dependency. The proposed method consists of two phases. One is the preprocessing phase at the rule compilation time which combines the integrity constraints and compiled axioms using theorem prover. This phase is divided into simplification and semantic integration. The other phase is the optimization phase, which makes an efficient access plan with information from the preprocessing. We reduced the optimization overhead, since we preprocess the integrity constraints at rule compilation time.
