Towards the support of integrated views of multiple databases: an aggregate schema facility

Abstract

Supporting multiple user views of databases is currently an important problem area in database management system development. An interesting facet of this problem arises whenever a user needs an integrated view of several distinct databases. Using traditional database concepts, an aggregate schema facility has been developed to address this problem. The basic functions of an aggregate schema facility are discussed, as well as their implementation in a CODASYL/DBTG-like environment. Interest in an aggregate schema facility grew out of a problem in restructuring large databases. The application of this facility to restructuring is discussed, as well as potential applications to dynamic translation and distributed databases.