A Hybrid Data Integration Approach Based on Specialized Mediators.

Data integration systems are one of the important issues in many distributed architectures like mediation systems. Mediators use a virtual global schema that generalizes over the relevant parts of the sources schemas. There are two basic approaches for designing a data integration system: Global As View (GAV) and Local As View (LAV). In the GAV approach, the global schema is defined in terms of the local sources schemas, while in the LA V approach, the global schema is defined independently of the local sources schemas. To better cope with heterogeneous data integration, this paper presents an integration approach of heterogeneous data. This approach, named HAV (Hybrid As View), aims at combining the best of GAV and LAV, and then reduces their limitations to improve the data integration effectiveness, flexibility and scalability. The paper deals with the problem of the mapping and the query processing and provides some formal definitions based on Lenzerini's formula for data integration. HAV is experimented on a case study and is evaluated qualitatively and quantitatively. [ABSTRACT FROM AUTHOR]