Performance Evaluation of an Optimistic Concurrency Control Algorithm for Temporal Databases

Abstract

We propose in this paper a performance study of an access concurrency control algorithm for temporal databases. This algorithm is based on the optimistic approach, which is, in our opinion, more suitable for temporal databases than the pessimistic methods. Indeed, our optimistic algorithm, in the contrary to the pessimistic ones, can exploit the temporal specifications to reduce the granule size and then to minimize the conflict degree. Moreover, it can detect, as soon as possible, all the conflict cases. By using the end of transaction marker technique, it has the merit to reduce to the maximum the period during which resources are locked in the validation phase. By carrying out a formal verification, based first on the serialization theory and next on the SPIN model checker, we have ensured that our algorithm operate correctly. Now, we proceed to its experimental evaluation vis-à-vis of other well-known concurrency control mechanisms based on an optimistic and pessimistic approach.