XML数据库并发控制机制的研究

并发控制是改善数据库系统事务性能的最重要的机制,多用户事务并发问题在XML原型数据库领域是一个难点。通过一种类XPath数据模型,定义基于此模型的几种XML数据库操作。在此基础上,提出一种基于XPath的锁协议(XPL)以及锁模型,并验证在此锁协议机制下的调度是可串行性调度,从而实现了XML原型数据库的多用户事务并发控制。最后通过实验对XPL协议的并发性能进行测试和分析。

Research on Concurrency Control Mechanism for XML Databases

Concurrency control is the most important way of improving the transaction capability of database system.And multiple-users concurrency transaction is also a difficulty in the field of Native XML Databases.In this paper,some kinds of XML Database operations based on the pseudo XPath Data Model are proposed.On the basis of this,an XPath-based Locking protocol(XPL),as well as a lock mode,is put forward and then the schedule within the locking protocol mentioned above is proved to be serializability.As a result,the Multiple-users concurrency transaction for Native XML Databases can be realized.The detailed performance evaluation results obtained by using typical experiments are also given to analyze the capability of concurrency for XPL protocol.