Operations of Homogenizing and Heterogenizing inFederated Database Systems
Ingo Schmitt · 1996
The federation of heterogeneous database systems is still a challenge for the database system research. A main topic in federated database systems is the process of overcoming the heterogeneity of component schemata and the process of deriving heterogeneous external schemata for global applications. Semantically rich data models increase the complexity of managing heterogeneity. In this paper heterogeneity of component schemata is overcome by homogenizing operations in a semantically poor data model. Heterogeneous external schemata can be derived from the federated schema by heterogenizing operations which are inverse to the homogenizing operations. Due to the homogenizing by decomposing of classes and heterogenizing by composing of classes, flexible schema transformations and integration is possible.