DWARF结构的存储策略及查询处理的研究与实现

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1、东北大学硕士学位论文Dwarf结构的存储策略及查询处理的研究与实现姓名：张斌申请学位级别：硕士专业：计算机软件与理论指导教师：鲍玉斌20060101东北大学硕士学位论文StudyandImplementationoftheStorageStrategyandtheQueryProcessBasedonDwarfStructureAbstractThetechnologyofOLAPisveryimportantindecisionsupportsystem，whichisusedtoaidknowledgeworkers’decisionandanalysis，andw

2、hichisusedtoanalyzehugeamountofdata．Inordertoreducethequeryresponsetime，weoughttocomputethecubeinadvance．Thecomputationofdatacubeisnecessarybutcostlyindatawarehouse．Itisbecomingoneoftheresearchfocusestoreducethecostofcomputingandstoringdatacube．Dwarfisaveryeffectivealgorithm，whichcompres

3、sesthecubebyeliminatingthesemanticredundancywhilecomputingadatacube．Comparedwithsomeothersemanticcompressingalgorithm，Dwarfhashighcompressionratio，butbecauseofitsstructurecharacteristic，Dwarfisslowerinqueryingandmoredifficultinupdating．BasedonanalyzingthecharacteristicofDwarfstructureand

4、OLAPquery，wedevisetwoclusteralgorithmsforOLAPquery：recursionclusteralgorithmthatcanspeeduppointqueryandhierarchyclusteralgorithmthatcanspeeduprangequery．ItisprovedbyourexperimentsthateachofthetwodifferentclusteralgorithmsCaneffectivelyspeedupitsintendedquerytype，buthavenoeffectonspeeding

5、upoppositequerytype．Later，afterweanalyzethecharacteristicofthediskI／OsysteminWindowsNToperatingsystem，aquerysystemforDwarfalgorithmisdevised，whichisbasedonusingauser—definedmemorybuffer．ThetruereasontodothisisthatthecompletelyrandomaccessuponDwarfmakesbothdiskcacheandintelligentpre—readi

6、nginWindowsNTOSinvalid．SeemedtothefunctionofthemainmemorymanagementinWindowsNTOS，ouruser-definedmemorybufferalsoworksinapagingmanner，butdifferentfromthereplacestrategyinWindowsNTOS，ouruser-definedmemorybufferreplacesuselesspagebasedonthevisitcountofthepagetobereplaced．Itisalsoprovedbyour

7、experimentsthattheuser—definedmemorybufferandthevisit·-count·-basedreplacestrategycombinetheadvantageofthetwoclusteralgorithms．Keywords：Cube，OLAP,Dwarf,recursionclusteralgorithm，hierarchyclusteralgorithm，user—definedmemorybuffer．．III．．独创性声明本人声明所呈交的学位论文是在导师的指导下完成的。论文中取得的研究