Fragmentation and query decomposition in the ECR model

Fragmentation and query decomposition are considered important issues in a distributed database environment. For a semantic data model (ECR data model), the types of fragmentation and the criteria they should follow is provided along with how global queries in a high-level language, GORDAS, are decomposed into local queries on the fragments. This technique may be used in a heterogeneous distributed database, where the global schema presented to the user is in the high-level ECR model.