数据库访问控制研究综述

信息技术的迅速发展使数据库面临的安全更加复杂，访问控制(Access Control)是数据库安全领域的一个重要部分。本文首先回顾了传统的数据库访问控制各自存在的缺点，并总结了传统访问控制的不足之处，由此引出了现代访问控制方法——使用控制(Usage Control，UCON)，在此基础上总结了数据库访问控制技术的发展现状，并指出了在此方面进行研究的难点和需要解决的关键问题，并对今后发展的趋势进行了展望。

Distribution and changes of B and Mo in Black Soils with Different Parent Materials in Jilin Province

With the rapid development of information and technology,database faces more serious security situation. Research in the access controls has been an important part of the area of the database. Firstly,we review traditional access controls and analysis shortcomings of them. Then,the paper summaries disadvantages of traditional access con- trols and introduces modern access control--usage control. Based on what we discuss,the paper gives a view of the development of the database access control. In conclusion. it points out the difficulties of research and the existing problems that must be solved. Finally,the future direction in this field is discussed.