A new approach for the integration of heterogeneous databases and information systems

This work presents the functional integration technique (FIT) as an approach and framework for integrating database systems and legacy systems using distributed objects architecture. FIT wraps each local system by a local view and provides methods to build global views that integrate local views. FIT common data model is a novel model that supports structure, semantic and behavior representation. We define the view definition language (VDL) and the view query language (VQL) to define and query FIT views. We propose the view correspondence schema (VCS) as a descriptive method to define view correspondences. We also study the different types of correspondences that can exist between the local views and provide the proper integration rule for each case. The FIT integration algorithm uses the VCS schema between local views to generate a global view that integrates them, resolving structure, semantic and behavior conflicts. The effectiveness of the FIT integration approach is verified through a case study that integrates two medical systems. We show how the FIT algorithm generates an integrated view for the two systems resolving different conflict types between them. The global view provides two integrated access methods; generic access using VQL and functional access based on system level behavior