Consistent query answering based on repairing inconsistent attributes with nulls

ISCAS OpenIR

	Consistent query answering based on repairing inconsistent attributes with nulls
	Liu, Jie (1); Ye, Dan (1); Wei, Jun (1); Huang, Fei (1); Zhong, Hua (1)
	2013
会议名称	18th International Conference on Database Systems for Advanced Applications, DASFAA 2013
页码	407-423
会议日期	April 22, 2013 - April 25, 2013
会议地点	Wuhan, China
收录类别	EI
出版地	Springer Verlag, Tiergartenstrasse 17, Heidelberg, D-69121, Germany
ISSN	3029743
ISBN	9783642374869
部门归属	(1) Institute of Software, Chinese Academy of Sciences, Beijing, 100190, China
摘要	Although integrity constraints can successfully capture data semantics, the actual data in the database often violates such constraints. A Consistent Query Answer (CQA) in a possibly inconsistent database is an answer which is true in every minimal repair of the database. It has been proved that for most constraints and queries CQA is a NP problem based on repairing by tuple deletions or tuple insertions. Furthermore, repairing by deleting tuples will also cause information losing. In this paper we present a new repair semantics named repairing with nulls, which replaces the inconsistent attribute values with nulls. To capture all the inconsistent attribute values, we study the transitivity of nulls and provide an algorithm to extend the original constraints. Based on repairing with nulls, there will be only one repair and CQA can be computed in PTIME by SQL query rewriting. Finally, we study the performance of our new approach for CQA by detailed experiments. © Springer-Verlag 2013.; Although integrity constraints can successfully capture data semantics, the actual data in the database often violates such constraints. A Consistent Query Answer (CQA) in a possibly inconsistent database is an answer which is true in every minimal repair of the database. It has been proved that for most constraints and queries CQA is a NP problem based on repairing by tuple deletions or tuple insertions. Furthermore, repairing by deleting tuples will also cause information losing. In this paper we present a new repair semantics named repairing with nulls, which replaces the inconsistent attribute values with nulls. To capture all the inconsistent attribute values, we study the transitivity of nulls and provide an algorithm to extend the original constraints. Based on repairing with nulls, there will be only one repair and CQA can be computed in PTIME by SQL query rewriting. Finally, we study the performance of our new approach for CQA by detailed experiments. © Springer-Verlag 2013.
语种	英语
内容类型	会议论文
URI标识	http://ir.iscas.ac.cn/handle/311060/16669
专题	中国科学院软件研究所
推荐引用方式 GB/T 7714	Liu, Jie ,Ye, Dan ,Wei, Jun ,et al. Consistent query answering based on repairing inconsistent attributes with nulls[C]. Springer Verlag, Tiergartenstrasse 17, Heidelberg, D-69121, Germany,2013:407-423.