基于數(shù)據(jù)為中心的XML文檔Twig查詢算法研究.pdf

1、東北大學(xué)碩士學(xué)位論文基于數(shù)據(jù)為中心的XML文檔Twig查詢算法研究姓名：董科申請學(xué)位級別：碩士專業(yè)：計算機(jī)系統(tǒng)結(jié)構(gòu)指導(dǎo)教師：王國仁20070101東北大學(xué)碩士學(xué)位論文StudyonAlgorithmsofTwigQueryProcessingonDataCentricXMLDocumentsAbstractXML(ExtensibleMarkupLanguage)hasbeenincreasinglyusedinW曲applicatio

2、nsandbecomeastandardfordatainterchangeOVertheIntemetNeverthelessalongwitlltheincreasingsizeofXMLdocumentsandcomplexityofevaluatingXMLqueries，existingqueryprocessingperformanceintraditionalwaywillmeetalimitationItiswellkn

3、ownthatmoreandmorenewmethodshavebeenavailabletOthisproblemUnlikeintraditionaldatabasesqueriesonXMLdocumentsaimatnotonlyelementcontentsbutalsostructuralrelationshipsbetweentaggedelementsPathexpressionisoneoftheapproacheso

4、fmeetingthequery，requirementsTherefore，queryprocessingbasedonpathexpressionbecomesthekeyforsuchqueriesConsequentlyevaluatingtheprimitivestructuralrelationshipsofpathexpression，includingparentchildandancestordesoendantist

5、hecoreissueforthequeryprocessingofXMLdataRecentlyproposedholisticstructuraljoinalgorithmsarepopularinprocessingsuchrelationshipsInordertoevaluateholistictwigquery，manyalgorithmshavebeencreatedRecentlyproposedholisticTwig

6、queryalgorithms，includingTwigStack，PPs，TagLevelandTJFastaretosolvethusproblemAllthesealgorithmstaketheadvantageofscanningXMLdocttmentonlyonceandregardTwigqueryasaholismButthesealgorithmsignorethecharacteristicofXMLdocume

7、nLSOweproposetwonewalgorithms—NestStackandCPJoin；thealgorithmseaRprocesstheTwigquerybaseonthecharacteristicofdataeentriedocumentUIlliketraditionalwaywebreakthetraditionaltwo—phasestrategyteducethesizeofintermediateresult

8、11leNestStackCaneffectivelyskiptheelementswhicharenestedelements，andtheCPJoincanefficientprocessthetwinnodesinXMLdocumentAfteraseriesofexperimentsonrealXMLdocumentsandsynthesizedocuments，aconclusionCanbedrawnthattheNestS