Recovering imprecise transactions with real-time constraints

Abstract

In real-time database systems, a transaction may not have enough time to complete. In such cases, partial, or imprecise, results can still be produced. The authors have proposed an imprecise result mechanism for producing partial results, which is used to implement timing error recovery in real-time database systems. They also present a model of real-time systems that distinguishes the external data consistency from the internal data consistency maintained by non-real-time systems. Providing a timely response may require sacrificing internal consistency. The authors discuss three examples that have different requirements of data consistency and present algorithms for implementing them.