This paper describes a general ~odel for distributed data (MOGADOR) together with a language for describing and manipulating dispersed data.In providing an homogeneous level for the description and the behaviour of distributed data bases, MOGADOR can be viewed also as a logical tool for designing heterogeneous distributed data bases management systems.
!. INTRODUCTION : DIFFERENT APPROACHES TO DISTRIBUTED DATA BASES MANAGEMENT SYSTEMSThe advent of computer networks and the increasing development of data base technology brought a great potential for sharing data among heterogeneous computing facilities.This area of research is currently refered to as distributed data bases, one of the main problems being the design and the implementation of a distributed data base management system (DDBMS) [12][23].In France, a national project ("SIRIUS") projet [24]) sponsored by IRIA, coordinates several research projets on this area such as the one described here which is in process at the Grenoble University. The second approach seems to be more realistic in the way that a great variety of DBMS are to day commercially available. Often in some big enterprises or administrations data processing has been made by sectorization then creating several data bases This research is supported by IRIA SIRIb~ Project (contract 77 076).