Using Ontologies for Semantic Query Optimization of XML Database
As XML has gained prevalence in recent years, the management of XML compliant structured-document database has become a very interesting and compelling research area. Effective query optimization is crucial to obtaining good performance from an XML database given a declarative query specification because of the much enlarged optimization space. Query rewriting techniques based on semantic knowledge have been used in database management systems, namely for query optimization. The main goal of query optimization is to rewrite a user query into another one that uses less time and/or less resources during the execution. When using those query optimization strategies the transformed queries are equivalent to the submitted ones. This paper presents a new approach of query optimization using ontology semantics for query processing within XML database. In fact, our approach shows how ontologies can effectively be exploited to rewrite a user query into another one such that the new query provides equally meaningful results that satisfy the intention of the user. Based on practical examples and their usefulness we develop a set of rewriting rules. In addition, we prove that the results of the query rewriting are semantically correct by using a logical model.
KeywordsQuery Processing User Query Semantic Knowledge Query Optimization Query Plan
Unable to display preview. Download preview PDF.
- 1.Amer-Yahia, S., Cho, S., Lakshmanan, L.V., Srivastava, D.: Minimization of Tree Pattern Queries. In: Proc. of SIGMOD, pp. 497–508 (2001)Google Scholar
- 2.Fernandez, M.F., Suciu, D.: Optimizing Regular Path Expressions Using Graph Schemas. In: Proc. of ICDE, pp. 14–23 (1998)Google Scholar
- 3.Chen, Z., Jagadish, H., Lakshmanan, L.V.S., et al.: From Tree Patterns to Generalized Tree Patterns; On Efficient Evaluation of XQuery. In: Proc. of 29th VLDB, pp. 237–248 (2003)Google Scholar
- 5.Amann, B., Fundulaki, I., Scholl, M., Beeri, C., Vercoustre, A.: Mapping XML Fragments to Community Web Ontologies. In: Proceedings of the 4th International Workshop on the Web and Databases (WebDB 2001), pp. 97–102 (2001)Google Scholar
- 6.Camillo, S.D., Heuser, C.A., Mello, R.S.: Querying Heterogeneous XML Sources through a Conceptual Schema. In: Proceedings of the 22nd International Conference on Conceptual Modeling (ER 2003), pp. 186–199 (2003)Google Scholar
- 8.Guarino, N., Giaretta, P.: Ontologies and knowledge bases: towards a terminological clarification. In: Knowledge Building Knowledge Sharing, pp. 25–32. ION Press (1995)Google Scholar
- 9.Noy, N., Hafner, C.D.: The state of the art in ontology design. AI Magazine 3, 53–74 (1997)Google Scholar
- 10.Chandrasekaran, B., Josephson, J., Benjamins, V.: What are ontologies, and why do we need them? In: IEEE Intelligent Systems, pp. 20–26 (1999)Google Scholar
- 14.Hsu, C.: Learning effective and robust knowledge for semantic query optimization (1996)Google Scholar
- 15.Peim, M., Franconi, E., Paton, N., Goble, C.: Query processing with description logic ontologies over object-wrapped databases. technical report, University of Manchester (2001)Google Scholar
- 16.Bergamaschi, S., Sartori, C., Beneventano, D., Vincini, M.: ODB-tools: A description logics based tool for schema validation and semantic query optimization in object oriented databases. In: Advances in Artificial Intelligence, 5th Congress of the Italian Association for Artificial Intelligence, Rome, Italy, pp. 435–438 (1997)Google Scholar