Research in Time-and-Error-Constrained Databases

时间和错误约束数据库的研究

• 批准号: 9008632
• 负责人: Gultekin Ozsoyoglu
• 金额: $ 19.9万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-15 至 1993-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9008632&HistoricalAwards=false
• 关键词: Research; Time; Error; Constrained; Databases

One may define a "time-constrained database" as a database that has strict timing constraints in (a) responding to queries, (b) processing transactions, and in (c) database maintenance. A "time-constrained query" has the form of "get the information x in no more than t time units". This project deals with the problem of processing arbitrary time-constrained queries in centralized and single-user time-constrained databases. Various ways of revising a query into one which has the most "informative" response and can be evaluated within the given time constraint with a controlled risk of overspending are investigated. Techniques for fragment selection and risk analysis are introduced. Semantic query processing techniques to control the query processing times are investigated. The expected outcome of this research is (i) a methodology to process queries with time constraints, (ii) a prototype time- constrained database management system and a performance evaluation using the prototype, and (iii) heuristics about the use of various options under different data characteristics. Potential applications of the research results are in those areas where time-critical database processing is important, e.g., scientific applications and manufacturing environments.

人们可以将“时间受限数据库”定义为在(a)响应查询、(b)处理事务以及(c)数据库维护方面具有严格时间约束的数据库。 “时间受限查询”的形式是“在不超过t个时间单位内获取信息x”。该项目解决在集中式和单用户时间受限数据库中处理任意时间受限查询的问题。研究了将查询修改为具有最“信息性”响应并且可以在给定时间限制内以受控的超支风险进行评估的查询的各种方法。介绍了片段选择和风险分析的技术。 研究了控制查询处理时间的语义查询处理技术。 这项研究的预期成果是（i）一种处理有时间限制的查询的方法，（ii）一个时间受限的数据库管理系统原型和使用该原型的性能评估，以及（iii）关于在不同数据特征下使用各种选项的启发式方法。 研究结果的潜在应用是那些对时间要求严格的数据库处理很重要的领域，例如科学应用和制造环境。