Research On Relational Database-based Ontology Storing

As the extension of current WWW (World Wild Web), the target of semantic Web is to provide a universal semantic framework for the realization of data sharing and integrating among different applications. Ontology is the basis of semantic Web and relational database is the storing way of most data on WWW. So, mutual rmapping between ontology and relational database scheme is an important part of research on semantic web, research on ontology storing based on relational database is one of relevant main issues. The studing works of this dissertation are as follows:Firstly, this dissertation introduced situation of ontology storing research and analyzed the issues existing in this field in details. Then, the relevant technologies, such as ontology describing language, ontology reasoner and ontology storing pattern, etc. are outlined and compared with each other from three aspects related with ontology storing.Secondly, on the basis of comparing the pros and cons of current ontology storing patterns based on relational database, the dissertation summarized the general principles of storing ontology in relational database. Next, according to this principle, this dissertation designed and implemented a mixed storing pattern called ROSP (Rdb_based Ontology Storing Pattern) of clear structure, high querying efficiency and good extension performance. At the same time, a group of reasonable experiment solutions testing contrastively querying efficiency and extension performance of this pattern are designed according to the principle of performance evaluation. The result shows that ROSP is more suitable for high efficiency storing of large scale ontology.Thirdly, the dissertation studied the optimization of ontology storing with sophicated relational database technology on the basis of ROSP. On the one hand, the importance of materialized view, clustered index and stored procedure in the optimization of quering efficiency are analyzed. On the other hand, this dissertation summarized the principles of updating automaticly ontology information with reference integrity constraint and updating trigger under different situations, and carried out corresponding test. The performance before optimization and after optimization was also comparaed.At the final, this dissertation designed and implemented a model system. This model can realize the automatic creation of ROSP, the automatic parsing and data storing of OWL ontology, and the semantic retrieval based on it. This dissertation described the modules, design method and disposing process in details, summarized the works of this dissertation and further research suggestions are gived.