Schema mappings and annotations in semantic integration of XML data in P2P data integration systems

The key problem in data integration systems is creating and maintaining mappings between schemas of heterogeneously structured data sources. The problem becomes increasingly important in P2P environment when new partners enter the system and their schemas evolve. In this work we focus on deriving mappings between XML schemas using their annotations in common domain ontology. A special attention is paid to conditional annotations, which are used when an XML schema models specialization. The presented approach underlies the implementation of SixP2P (Semantic Integration of XML data in P2P environment) system.