Integrating Heterogeneous Data Source Using Ontology

Integrating data from multiple heterogeneous sources entail dealing with different data models, schemas and query languages. The burgeoning Semantic Web has provided several new methods for data integration. This paper focuses on integration of relational database and XML data. To solve the problem we propose an ontologybased approach. A semantic integration infrastructure for heterogeneous data sources is presented. In this infrastructure, ontology is used as the mediated schema for the representation of the data source semantics. To model different source schemas, we propose a describing method based on RDF graph patterns. The semantic mappings between source schema and RDF ontology are described declaratively using SPARQL queries. The semantic of query rewriting is further discussed and a query rewriting algorithm is presented.