Understanding Autonomy and Consistency in Multidatabase Systems

多数据库系统响应了组织支持应用程序的需求，这些应用程序需要由几个自治的、可能是不同种类的数据库系统维护的信息。多数据库系统的一个基本要求是保持各个数据库系统的自主性。然而，自主性需求在维护这些系统中的传统数据库一致性方面造成了问题，原因是自主性和一致性是相互冲突的需求。试图在这两个要求之间取得平衡的努力集中在新的正确性标准上。然而，关于(A)自主要求的语义和(B)其对一致性要求和实施考虑的影响的分析很少。本研究的目的是通过应用统一的规范技术来表达自主性要求和正确性标准，从而系统地分析自主性和一致性，从而明确它们之间的关系并确定它们之间的权衡。通过了解这些权衡及其对数据库系统不同部分的影响，这项工作将有助于开发多数据库系统，并将对要求自主性和一致性的其他系统的集成产生影响。

Multidatabase systems respond to the need of organizations to support applications that require information maintained by several autonomous and possibly heterogeneous database systems. A fundamental requirement underlying Multidatabase systems is the preservation of the autonomy of the individual database systems. However, autonomy requirements cause problems in maintaining traditional database consistency in these systems, the reason being that autonomy and consistency are conflicting requirements. Attempts to strike a balance between these two requirements have focused on new correctness criteria. However, very little analysis has been done with respect to (a) the semantics of autonomy requirements and (b) their implications for both consistency requirements and implementation considerations. The goal of this research is to systematically analyze autonomy and consistency by applying a uniform specification technique to express autonomy requirements and correctness criteria, thereby explicitly showing their relationships and identifying the tradeoffs between them. By understanding these tradeoffs and their effects on different parts of a database system, this work will help in the development of Multidatabase systems and will have an impact on the integration of other systems in which autonomy and consistency are requirements.