Optimization technique for query answering based on semantic

Representative optimization techniques for semantic query answering in current literatures are presented. Semantic query answering is the most important foundation for other services provided by the knowledge base on the Semantic Web. Great variety of entities existing of ABox in the knowledge base, which makes semantic query answering inefficient. In order to improve performance of semantic query answering, the query is transformed into the basic expression form of a notion based on the basic optimization principle. This kind of semantic query answering method reduces the reasoning loads to the greatest extent, so it is more efficient than the original.