Research On The Approach For Ontology-based Heterogeneous Data Integration

Following the development of computer technology and network technology, Modern Enterprises have developed large amount of information manage systems based on different platforms of software and hardware in the progress of information realization. In order to get better using of the information on internet, and to avoid the overlapped construction in progress of enterprise information realization and to make full use of the legacy information manage systems, we should integrate the heterogeneous data which is distributed in geographical, autonomy in management, and heterogeneous in model. The goal of the heterogeneous data source integration is to realize information sharing and to resolve the problems caused by "information isolated island" witch include repeat entry , resource wastage, data inconsistency, etc. Meanwhile, the research will provide a basic data platform to synthetic information query and decision support service. Because of the advantage on knowledge and concept representation and reasoning, ontology is used in the field of heterogeneous data integration.In this thesis, we research the problem of heterogeneous data integration whch appeared in the progress of enterprise information realization. The ontology is introduced to the field of data integration. The main work and creative contributions of this paper are as follows:(1) Based on the research of existing data integration systems, we designed a data integration system and proposed a data integration framework based on Mediator -Wrapper approach.(2) We discussed the approach of global ontology and local ontology construction, then constructed the ontology by a tool called Protege.(3) This paper also researched two key problems: ontology mapping and query processing, and we established the mappings between global ontology and local ontology and the mapping between local ontology and local data sources.(4) Referencing to the query expressions in XML and relation data source, we proposed a query operation expression of ontology concepts and an approach of query division based on query operation chart. We divided the global query into several local queries and realized the integrated information retrieval on two typical heterogeneous data sources: XML and RDB, which are based on two different data models.