不确定数据库中基于x-tuple的高效Top-k查询处理算法.pdf

ISSN 计算机研究与发展 1000—1239／CN11-1777／TP of Researchand Journal Computer Development 不确定数据库中基于X—tuple的高效Top一七查询处理算法 刘德喜 万常选 刘喜平 (江西财经大学信息管理学院 南昌 330013) (江西省高校数据与知识工程重点实验室 南昌 330013) (dexiliu@gmail．corn) Efficient of Based inUncertainDatabase ProcessingX·-Tuple Top‘-kQueries Liu Liu Dexi，Wan Changxuan，andXiping (School 330013) ofInformationTechnology，JiangxiUniversityofFinanceEconomics，Nanchang Dataand 330013) (JiangxiKeyLaboratoryof KnowledgeEngineering，Nanchang AbstractLike intraditional inuncertaindatabasesare top-k databases，top—kqueries quitepopular andusefulduetoitswide with traditionaldatabases， applicationusage．However，comparedtop一是in overuncertaindatabasearemore becauseoftheexistenceof queries complicated exponentialpossible kindsof rulesare inthe worlds．Often，two considereduncertain generation and istheunionofthe exclusive．U—kRanks mutuallyexclusive．An．33一tuple tuplesmutually queries consider in as oneandreturnthe whichhasthe eachalternative z—tuplesingle tuple highestprobability at k ora matterwhich an rank．However，no appearingtop given alternative(tuple)ofz—tuple ina is believedthatthis inthesame world，it appearspossible undoubtedly z—tupleappears possible worl