期刊名称：International Journal of Database Management Systems
印刷版ISSN：0975-5985
电子版ISSN：0975-5705
出版年度：2010
卷号：2
期号：1
出版社：Academy & Industry Research Collaboration Center (AIRCC)
摘要：Several database (DB) applications are temporal of nature and require a special treatment. In particular, in the field of concurrency control (CC) which takes new dimensions when applied to temporal DB (TDB). The CC algorithms proposed for TDB have tried to find solutions for the CC to improve their performances. Especially, they have tried, by benefiting from the characteristics of the TDB, to decrease the degree of conflict, and this by the use of à priori knowledge or the reduction of the granule sizes. But these algorithms have not reached the fixed objectives. To contribute to the edification of a CC component suitable for TDB, we propose in this paper a complete study of access concurrency control in TDB. We have chosen to build our algorithms according to the optimistic methods, which are, in our opinion, more suitable for TDB than the pessimistic methods. Indeed, our optimistic algorithms can exploit the temporal specifications to reduce the granule size and then to minimize the conflict degree. Moreover, they can detect, as soon as possible, all the conflict cases. By using the end of transaction marker technique, they have the merit to reduce to the maximum the period during which resources are locked in the validation phase. To be sure that our algorithms operate correctly, we have carried out a formal verification, based first on the serialization theory and next on the SPIN model checker. Then, we have made a performance evaluation vis-à-vis of other wellknown concurrency control algorithms based on optimistic and pessimistic approaches, to show that our propositions ameliorate the performances in the large majority of the cases.
