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1、Data&KnowledgeEngineering72(2012)31–62ContentslistsavailableatSciVerseScienceDirectData&KnowledgeEngineeringjournalhomepage:www.elsevier.com/locate/datak3S:Processingtree-patternXMLquerieswithalllogicaloperatorsa,⁎,MostafaS.Haghjooa,1b,2SayyedKamyarIzadi,TheoHärderaDepartmentofCompu
2、terEngineering,IranUniversityofScience&Technology,Tehran,IranbDepartmentofComputerScience,UniversityofKaiserslautern,D-67663Kaiserslautern,GermanyarticleinfoabstractArticlehistory:XMLisatree-baseddatarepresentationformatwhichcombinesdataandstructure.Therefore,Received24May2010XMLque
3、riesnotonlycontainpredicatestofilterdatabutalsorefertorelationshipsbetweendoc-Receivedinrevisedform24August2011umentelementssearched.TheexistingelementsinanXMLqueryareconnectedtoeachotherAccepted7September2011usingatree-patternstructure,calledQueryTreePattern(QTP).Findingelementsofa
4、document,Availableonline21September2011whichsatisfythegivenQTP,isthemaintaskduringqueryexecution.Tooptimizethisprocessing,wepresentedtwomethodsin[13].InsteadofdirectlyexecutingtheQTPagainstthedocument,ourmethodsfirstevaluateaguidancestructure,calledQueryGuide.Usingtheextractedinform
5、a-tion,calledmatchpattern,weprovidedafocuseddocumentaccessandminimizedtherequiredI/O.However,weonlysupportedthelogicaloperatorAND(calledAND-QTPs).Inthispaper,weuseanewstructure,calledEvaluationTree,toexecuteQTPs.WealsoextendourmethodtosupportQTPshavinglogicaloperatorsOR,XOR,andNOT.P
6、arsingQTPsintosomeAND-QTPsistypicallyassumednon-efficient.ToprocessQTPshavinglogicaloperatorsORandNOT,wethereforeparsethembutweuseanefficientmethodtopreventredundantI/OandQTPmatching.ThisisdonebyoptimizingtheselectionofmatchpatternswhichwerederivedfromtheQuery-GuideduringQTPparsing.
7、Asaresult,QTPexecutionisnotinefficientanymore.©2011ElsevierB.V.Allrightsreserved.1.IntroductionTheflexibilityofXMLprovidessuitabledatarepresentationformatsformanyapplications,especiallyforthosedealingwithsemi-structureddata.Furthermore,theemergenceofXMLdatabasemanagementsystems(XDBM
8、Ss)isaresponsetothe
