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金澈清,刘辉平,周傲英.基于函数依赖与条件约束的数据修复方法.软件学报,2016,27(7):1671-1684 |
基于函数依赖与条件约束的数据修复方法 |
Functional Dependency and Conditional Constraint Based Data Repair |
投稿时间:2015-10-09 修订日期:2016-01-12 |
DOI:10.13328/j.cnki.jos.005037 |
中文关键词: 数据质量 数据修复 函数依赖 条件约束 等价类 |
英文关键词:data quality data repair functional dependency conditional constraint equivalence class |
基金项目:国家重点基础研究发展计划(973)(2012CB316203);国家自然科学基金(61370101,U1501252,61532021);上海市教委科研创新重点项目(14ZZ045) |
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全文下载次数: 1985 |
中文摘要: |
随着经济与信息技术的发展,在许多应用中均产生大量数据.然而,受硬件设备、人工操作、多源数据集成等诸多因素的影响,在这些应用之中往往存在较为严重的数据质量问题,特别是不一致性问题,从而无法有效管理数据.因此,首要的任务就是开发新型数据清洗技术来提升数据质量,以支持后续的数据管理与分析.现有工作主要研究基于函数依赖的数据修复技术,即以函数依赖来描述数据一致性约束,通过变更数据库中部分元组的属性值(而非增加/删除元组)来使得整个数据库遵循函数依赖集合.从一致性约束描述的角度来看,函数依赖并非是唯一的表达方式,还存在其他表达方式,例如硬约束、数量约束、等值约束、非等值约束等.然而,随着一致性约束种类的增加,其处理难度也远比仅有函数依赖的场景要困难.考虑以函数依赖与其他一致性约束共同表述数据库的一致性约束,并在此基础上设计数据修复算法,从而提升数据质量.实验结果表明,所提方法的执行效率较高. |
英文摘要: |
Along with the development of economy and information technology, a large amount of data are produced in many applications. However, due to the influence of some factors, such as hardware equipments, manual operations, and multi-source data integration, serious data quality issues sunch as data inconsistency arise, which makes it more challenging to manage data effectively. Hence, it is crucial to develop new data cleaning technology to improve data quality to better support data management and analysis. Existing work in this area mainly focuses on the situation where functional dependencies are used to describe data inconsistency. Once some violations are detected, some tuples must be changed to suit for the functional dependency set via update (instead of insert or delete). Besides functional dependency, there also exist other types of constraints, such as the hard constraint, quantity constraint, equivalent constraint, and non-equivalent constraint. However, it becomes more difficult when more inconsistent conditions are involved. This paper addresses the general scenario where functional dependencies and other constraints co-exist. Corresponding data repair algorithm is designed to improve the data quality effectively. Experimental results show that the proposed method performs effectively and efficiently. |
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