Theoretical Investigation of Information Sharing for Semantic and Object-Oriented Databases

语义和面向对象数据库信息共享的理论研究

• 批准号: 9107055
• 负责人: Richard Hull
• 金额: $ 16.7万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-01 至 1994-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9107055&HistoricalAwards=false
• 关键词: Theoretical; Investigation; Information; Sharing; Semantic

This research is developing languages and mechanisms for restructuring and merging information from disparate databases, and is studying the theoretical foundations of such languages.The research uses the PI's formally defined ILOG languages, which permit the declarative specification of database restructuring. Certain technical properties of these languagesprovide a strong connection to logic programming. The research is also developing extensions to ILOG for data merging; a central problem here involves determining when object identifiers (OIDs) in two or more distinct databases refer to the same object "in the world", and developing appropriate mechanisms for "merging" the OIDs in this case. Specific theoretical questions under study include: attempting to characterize when two (restructuring or merging) programs are equivalent; exploring algebraic properties of programs (e.g., associativity, distributivity);developing algorithms for the translation of queries against restructured, merged databases; and for incrementally updating such databases if they are materialized. Experimental work will be performed to test the algorithms and view update methodologiesunder realistic conditions. The results obtained by the researchwill provide a crucial component for all database applications which involve data sharing.

这项研究正在开发用于重组和合并来自不同数据库的信息的语言和机制，并正在研究这些语言的理论基础。研究使用PI的正式定义的ILOG语言，该语言允许对数据库重组进行声明性规范。这些语言的某些技术特性提供了与逻辑编程的紧密联系。这项研究还在开发用于数据合并的ILOG扩展；这里的一个中心问题涉及确定两个或更多不同数据库中的对象标识符(OID)何时引用“世界上”相同的对象，并开发在这种情况下“合并”OID的适当机制。正在研究的具体理论问题包括：试图表征两个(重组或合并)程序何时等价；探索程序的代数属性(例如，关联性、分布性)；开发针对重构的、合并的数据库的查询翻译算法；以及如果这些数据库被物化，则增量地更新这些数据库。将进行实验工作，以测试算法和查看现实条件下的更新方法。研究取得的成果将为涉及数据共享的所有数据库应用程序提供一个重要组成部分。