TOPAZ:a tool kit for the assembly of transaction managers for non-standard applications

'Advanced database applications', such as CAD/CAM, CASE, large AI applications or image and voice processing, place demands on transaction management which differ substantially from those in traditional database applications. In particular, there is a need to support 'enriched' data models (which include, for example, complex objects or version and configuration management), 'synergistic' cooperative work, and application- or user-supported consistency. Unfortunately, the demands are not only sophisticated but also diversified, which means that different application areas might even place contradictory demands on transaction management. This paper deals with these problems and offers a solution by introducing a flexible and adaptable tool kit approach for transaction management

Specifying Interdatabase Dependencies in a Multidatabase Environment

The problem of interdatabase dependencies and the effect they have on applications updating interdependent data are addressed. A model that allows specifications of constraints among multiple databases in a declarative fashion is proposed. The separation of the constraints from the application programs facilitates the maintenance of data constraints and allows flexibility in their implementation. It allows investigation of various mechanisms for enforcing the constraints, independently of the application programs. By grouping the constraints together, it is possible to check their completeness and discover possible contradictions among them. The concepts of polytransactions, which use interdatabase dependencies to generate a series of related transactions that maintain mutual consistency among interrelated databases, is discussed

Using Polytransactions to Manage Interdependent Data

Many large companies use multiple databases to serve the needs of various application systems. One of the significant problems in managing these databases is maintaining the consistency of inter-related data in an environment consisting of multiple semi-autonomous and heterogeneous systems. We use the term interdependent data to imply that two or more data items stored in different databases are related through an integrity constraint that specifies the data dependency and the consistency requirements between these data items. Management of such data implies that a certain degree of mutual consistency among the interdependent data is maintained. Therefore, the manipulation, including concurrent updates, of the interdependent data must be controlled