多数据库事务处理模型中局部代理的设计与实现

在多数据库事务处理模型中，局部代理提供了全局事务管理层与局部数据库系统的接口，它使多数据库系统能够对分布在不同站点的局部数据库进行透明访问。文中提出了基于两阶段代理（２ＰＣＡ）的局部代理模型，它集成了支持两阶段提交或单阶段提并的数据库系统、以及并不支持事务提交协议的文件系统。文中还介绍了采用专用接口和ＯＤＢＣ两种实现局部代理的方法。文中着重介绍了使用ＯＤＢＣ方法的具体实现，并对两种方法实现的局部代

DESIGN AND IMPLEMENTATION OF THE LOCAL AGENT IN A MULTIDATABASE TRANSACTION MODEL

In a multidatabase transaction model, local agent is the interface between the global transaction manager and the local database systems. It provides transparently accessing local database distributed at different sites for multidatabase systems.Here presented is the local agent model based on two\|phase commit agent(2PCA). The model integrates database systems that support two\|phase commit protocol or one\|phase commit protocol,and file systems without any transaction processsing protocol. Two methods, using special interface and ODBC, which implement the local agent, are also introduced. The concrete implementation using ODBC is specially addressed. The performance comparison between the two methods is also discussed.