Research in Time-and-Error-Constrained Databases

可以将“时间约束数据库”定义为 在（a）响应查询，（B）中有严格的时间限制 处理交易，以及（c）数据库维护。一 “时间约束查询”的形式为“获取信息x 在不超过t个时间单位内”。本项目涉及 处理任意时间约束查询的问题 集中式和单用户时间受限的数据库。各种 将查询修改为具有最多 “信息”的反应，并可以在给定的时间内进行评估 控制超支风险的约束是 研究了碎片选择和风险分析技术 阐述 语义查询处理技术来控制 调查查询处理时间。 本研究的预期成果是（一）一种方法， 处理具有时间约束的查询，（ii）原型时间- 约束数据库管理系统和性能 使用原型进行评估，以及（iii）关于 根据不同的数据特征使用不同的选项。 研究结果的潜在应用领域是这些领域 在时间关键的数据库处理很重要的情况下，例如， 科学应用和制造环境。

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.