Implementation of a Speculative Concurrency Controller

Many scheduling algorithms for databases have been developed in order to improve transaction responsiveness. Some developed algorithms meet special needs of real-time databases. These algorithms however, deal with temporal execution aspects , often disregarding semantics of data usage which could further improve performance. One such algorithm is Speculative Concurrency Control , which uses execution redundancy by forking to improve performance. A simpliied version of this algorithm has been implemented as a concur-rency controller for an object oriented real-time database. This paper describes the experiences with the implementation, explains the reasons for only implementing a subset, and indicates required extensions to implement the complete algorithm. Also provided is a theoretical evaluation of the algorithms performance and scalability.