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：3
DOI：10.5121/ijdms.2010.2310
出版社：Academy & Industry Research Collaboration Center (AIRCC)
摘要：In any database environment either wired or wireless, if multiple host access similar data items it may lead to concurrent access anomalies. As disconnections and mobility are the common characteristics in mobile environment, preserving consistency in presence of concurrent access is a challenging issue. Most of the approaches use locking mechanisms to achieve concurrency control. This leads to increase in blocking and abort rate in mobile environments. However the dynamic timer adjustment strategies may use locking mechanism to efficiently implement concurrency control. To reduce deadlocks and blocking of resources an enhanced optimistic approach for concurrency control is proposed. To show the effectiveness of the commit protocols in mobile environments, a simulator is designed and implemented to demonstrate how the transactions are committed and how the data consistency is maintained when the transactions are executed concurrently. The simulator was tested for both pessimistic and optimistic approaches
关键词：Concurrency Control; Coordinator; Participant; Mobile Host; Fixed Host; Transaction
