INTEGRATING HETEROGENEOUS DISTRIBUTED DATABASE SYSTEM

This paper demonstrates various aspects of resolving possible data con flicts occurring in the database integration process. A general model of a Heterogeneous Distributed Database System (HDDBS) based on a rela tional data model is presented. We also discuss the problems of hetero geneous database integration and the principal user requirements, toge ther with design and implementation issues. The HDDBS suppresses diffe rences of DBMS, language, and data models among the databases and prov ides users with a unified global schema and a single high-level query language. There are three principal research goals of the paper. The f irst goal is to develop appropriate language constructs for accessing and integrating heterogeneous databases. The second goal is to discove r effective global and local optimization techniques. The final goal i s to design methods for handling incompatible data representations and inconsistent data.