A Semantic Approach to Enforce Correctness of Data Distribution Schemes

Abstract

SQL, the Xplain data language and two entity-relationship approaches have been examined for their usability in the specification of data distribution. It is shown to be difficult to enforce correctness of fragmentation if all possible kinds of fragmentation are allowed. To solve this problem, a new approach to the design of data distribution schemes has been developed. This approach is based on a semantic meta model for fragmentation and allocation with additional restrictions. Only two kinds of horizontal fragmentation are allowed. Vertical fragmentation is not supported, though the possibility of local vertical fragmentation is not excluded