Most current approaches to concurrency control in database systems rely on locking of data objects as a control mechanism. In this paper, two families of nonlocking concurrency controls are presented. The methods used are “optimistic ” in the sense that they rely mainly on transaction backup as a

-time groupware systems from other multi-user systems and dis-cusses their concurrency control requirements. An algorithm for concurrency control in real-time groupware systems is then presented. The advantages of this algorithm are its sim-plicity of use and its responsiveness: users can operate di

In this paper we survey, consolidate, and present the state of the art in distributed database concurrency control. The heart of our analysts is a decomposition of the concurrency control problem into two major subproblems: read-write and write-write synchronization. We describe a series

Concurrency control has been thoroughly studied in the context of traditional database applications such as banking and airline reservations systems. There are relatively few studies, however, that address the concurrency control issues of advanced database applications such as CAD/CAM and software

A “majority consensus ” algorithm which represents a new solution to the update synchronization problem for multiple copy databases is presented. The algorithm embodies distributed control and can function effectively in the presence of communication and database site outages. The correctness

In this paper we survey, consolidate, and present the state of the art in distributed database concurrency control. The heart of our analysts is a decomposition of the concurrency control problem into two major subproblems: read-write and write-write synchronization. We describe a series

As the demand for ever-larger knowledge bases grows, knowledge base management techniques assume paramount importance. In this paper we show that large, multi-user knowledge bases need concurrency control. We discuss known techniques from database concurrency control and explain

Developing concurrent applications is not a trivial task. As programs grow larger and become more complex, advanced concurrency control mechanisms are needed to ensure that application consistency is not compromised. Managing mutual exclusion on a per-object basis is not sufficient to guarantee

-text of concurrency because of the use of constraints for communication and control, and in the context of AI because of the availability of simple yet powerful mechanisms for controlling inference, and the promise that very rich representational/programming languages, sharing the same set of abstract properties, may

A number of recent studies have examined the performance of concurrency control algorithms for database management systems. The results reported to date, rather than being definitive, have tended to be contradictory. In this paper, rather than presenting “yet another algorithm performance study