Concurrency and Communication in Transaction Logic.

Abstract

In previous work, we developed Transaction Logic (or T R), which deals with state changes in deductive databases. T R provides a logical framework in which elementary database updates and queries can be combined into complex database transactions. T R accounts not only for the updates themselves, but also for important related problems, such as the order of update operations, non-determinism, and transaction failure and rollback. In the present paper, we propose Concurrent Transaction Logic (or CT R), which extends Transaction Logic with connectives for modeling the concurrent execution of complex processes. Concurrent processes in CT R execute in an interleaved fashion and can communicate and synchronize themselves. Like classical logic, CT R has a "Horn" fragment that has both a procedural and a declarative semantics, in which users can program and execute database transactions. CT R is thus a deductive database language that integrates concurrency, communication, and updates. All t...