Interoperation of independent, heterogeneous and distributed databases. Methodology and CASE support: the InterDB approach

Accessing and managing data from several existing independent databases pose complex problems that can be classified into platform, DMS, location and semantic levels. This paper describes a general architecture, a methodology and a CASE environment intended to address the problem of providing users and programmers with an abstract interface to independent heterogeneous and distributed databases. The architecture comprises a hierarchy of mediators that dynamically transform actual data into a virtual homogeneous database. Each layer provides a certain kind of independence. The InterDB approach provides a complete methodology to define this architecture, including schema recovery through reverse engineering, database integration and mapping building. The methodology is supported by the DB-MAIN CASE tool that helps to generate the mediators and their repository.