Heterogeneous information systems: understanding integration

Research in heterogeneous database systems has provided the basis for the development of integration tools or frameworks. These tools are used to build systems that provide information from multiple disparate systems or data sources. As many as thirty commercial frameworks exist for integrating heterogeneous database systems and numerous integrated systems are being developed for organizations with multiple information source requirements. Unfortunately, among integration framework and system developers there is little agreement on the definition of integration or on how to describe the frameworks and what they do. The authors present a definition of integration and define parameters for describing, specifying, and comparing integration frameworks and integrated systems. The parameters are based on the integration space where the dimensions define the hiding or exposing of heterogeneities in source, scheme, data model, time/context and dependencies. The authors use these dimensions in specifications to define the level of integration provided by the integration framework or integrated system