摘要
研究内置谓词函数依赖及其推理规则。首先提出内置谓词函数依赖,定义了内置谓词函数依赖的语法和语义;其次提出属性-约束集闭包概念,提出计算属性-约束集闭包的算法,判断内置谓词函数依赖逻辑蕴涵;然后提出内置谓词函数依赖的推理规则集A,证明推理规则集A是可靠且完备的,用于内置谓词函数依赖蕴涵分析的形式化证明;最后讨论了内置谓词函数依赖的应用。
The increasing demand for data quality technology has motivated revisions of classical dependencies to capture more in- consistencies in rcal-life data. A class of integrity constraints, referred to as functional dependencies with built-in predicates （PFDs）, is proposed for relational databases and their axiomatization is investigated. In contrast to traditional functional dependencies （FDs） developed mainly for schema design, PFDs generalize the notions of FDs to apply to subsets of relations specified by constraints in the context of interpreted data, and aim at capturing the consistency of data by enforcing bindings of ranges of semantically related values. For the implication analysis of PFDs, which is to decide whether or not a set of PFDs entails another PFD, we provide an inference system analo- gous to Armstrong＇s axioms for FDs, and prove the soundness and completeness of the inference system. This work is a step towards a practical constraint-based method for improving data quality since inconsistencies and errors in databases often emerge as violations of integrity constraints.
出处
《国防科技大学学报》
EI
CAS
CSCD
北大核心
2009年第5期58-63,共6页
Journal of National University of Defense Technology
基金
国家自然科学基金资助项目(60902094
60903225
70701038
60903206)
关键词
函数依赖
内置谓词
推理规则
逻辑蕴涵
可靠性
完备性
functional dependencies
built-in predicates
inference rule
logical implication
soundness
completeness
