Dynamic Integrity Constraints In Databases

动态完整性约束出现在许多传统和非传统数据库应用程序中；然而，当前的数据库管理系统不支持此类约束。这个项目关注于检查数据库中动态完整性约束的有效方法。过去时态逻辑和过去度量时态逻辑被提出作为约束语言，使得定性和定量的时态条件的表达成为可能。该项目包括开发和实现一种将动态完整性检查简化为静态完整性检查的方法。如果使用此方法，则不必存储过去的数据库状态以进行动态完整性检查。相反，压缩的历史信息作为辅助关系存储在每个数据库状态中。所需辅助关系的定义是从约束中自动导出的。还将讨论优化约束检查的技术以及将这一新方法与现有数据库管理系统相结合而产生的问题。拟议的研究将大大扩大数据库管理系统的应用范围，并使这些系统更容易与实时过程相结合。

Dynamic integrity constraints arise in many traditional and non- traditional database applications; however, such constraints are not supported by current database management systems. This project focuses on efficient methods for checking dynamic integrity constraints in databases. Past Temporal Logic and Past Metric Temporal Logic are proposed as constraint languages, making it possible to formulate both qualitative and quantitative temporal conditions. The project includes the development and the implementation of a method to reduce dynamic integrity checking to static integrity checking. If this method is used, past database states do not have to be stored for the purpose of dynamic integrity checking. Instead, compressed historical information is stored in every database state as auxiliary relations. The definitions of the needed auxiliary relations are automatically derived from the constraints. Techniques that optimize constraint checking and issues that arise from the integration of this new method with existing database management systems will also be addressed. The proposed research will significantly enlarge the application scope of database management systems and will make it easier to integrate these systems with real-time processes.