Operational software for restructuring

A high-level "access path" approach to database restructuring is described and contrasted with the "elementary operations" approach taken by mo~t restructuring systems. With the elementary operations approach, restructuring is viewed as a sequence of basic or "primitive" operations which manipulate a source database in order to convert it into a target database. In the access path approach, restructuring is seen as the process of accessing a body of information represented by the source data, and constructing the target database representation of the same information. While the elementary operations approach is useful for restructuring hierarchical databases, it does not generalize well for networks. The access path approach is bettersuited to the complex structures possible in network databases. The access path approach permits the specification of complex restructuring transformations in terms of application-oriented concepts such as access strategies and selection criteria. A non-procedural Network Restructuring Language (NRL) based on this approach is presented, and an example of its use in restructuring is given. The architecture of an NRL-driven Restructurer for network databases is described.