msda

In order to improve system performance , MSDA introduces access decision cache .

为了提高系统性能，MSDA在客体管理器中引入了访问判定缓存。

In addition , MSDA adopts access context stack to support controlled access mechanisms such as views and stored procedures .

此外还引入了访问上下文栈来支持视图和存储过程这类的受控访问机制。

This paper describes the implementation of MSDA in LOIS SDBMS v3.0 and analyzes the performance penalty brought about by MSDA .

给出了MSDA在LOISSDBMSv3.0中的实现，并通过实验给出了MSDA对目标系统的性能影响分析。

According to the requirements brought out by MSDA , a DBMS-oriented access control model ( DACM ) is presented , which is based on the adaptation research of RBAC model .

在MSDA的基础上，面向数据库系统进行了访问控制模型的适应性研究，提出了一个基于RBAC模型的数据库系统访问控制模型（DACM）。

As the result , MSDA separates access control decision and enforcement , solves the problems of supporting multiple policies in DBMS , fits well with main streams database systems , and will not influence the performance of target system to much .

结果表明，MSDA将访问控制判定与实施分离，既能充分解决数据库系统中支持多安全策略的相关问题，同时能够与当前主流关系数据库系统相匹配，不会造成目标系统性能的显著下降。