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1、東南大學博士學位論文數(shù)據(jù)倉庫物化視圖在線算法研究姓名：張柏禮申請學位級別：博士專業(yè)：計算機應用技術(shù)指導教師：孫志揮20050701AbstractAdatewarehouseisadatarepository,whichcollectsandmaintainsalargemountofdatafrommullipledism'buted，autonomousandpossiblyheterogeneousdatasoIM．Oftenthedataisstoredintheformofmaterializedview3forthepurposeefficientlyimpl
2、ementingdccision-suppo仳orOLAPqueries．Firstly,theselectionofviewsformaterializationisoneofthemostissuesinthedesigndatewarehouse,it’sgoalistoselect∞appropriatesetofviewsthatminimizestotalqueryresponsetimeand／orthecostofmaintainingtheselectedviews,givonalimitedamountofrasonsce，e．g．，storagesp
3、ace，materializationtime，ortotalviewmaIntanancetime．Secondly,maintaininglotsofmaterializedviewsischallenging．especiallyffthedatasources2reautonomousandviewsofthedataatthedatawarehousespanmultiplesoume“q．Theviewshavetobemaintainedintimetoreflecttheupdatesdoneagainstthebaserelationsstoredatt
4、hevariousdatesources．n圮e伍cientmaintenanceofmaterializedviewshasbecomeanotherimportantresearchiss∞．Theusualmethodsis廿扭tthematerializedviewsaraselectedandmaintainedoffline。forexample,thestaticselectionalgorithmofviewisemployedtogenerateorregeneratethematerializedviewset，andbatchupdatepolicy
5、isusedtomaintainthematnight，However,wheremtheamountofdataenteringawerchousc,thequeryloads，andtheneedtoobtain叩-to-dateresponsesareauincreasing,the‘'night"’timeavailableformakingthewarehouseup-to-dateisshrinking．Theseu'andsnecessitateefficientonlinealgorithmsformaterializedviews．Inthispaper
6、,itisemphasizedtomakedeeperresearchontheselectionalgorithmsandmaintenancealgorithmsofmaterializedviewsduringthedatawarehouseon-line．Themaincontributionsofthisdissertationareasfollows：(1)Tosolvetheshortageofthestaticselectionalgorithmofmaterializedview,thepaperpresentsPMVS．preprocessorofma
7、terializedviewselectionapproach．PMVSmakesu∞ofthequerysparsenessanddatasparsenassinmulti-dimensionaldatasets，andreducesthetimecomplex(searchspacc)ofthestaticselectionalgorithm，Sothecostofstaticalgorithmsonspaceandtimecanbecutdowntofitforonlinedemand．(2)Preseataimprov
