基于連接索引的查詢優(yōu)化研究

1、華中科技大學(xué)碩士學(xué)位論文基于連接索引的查詢優(yōu)化研究姓名：倪志鵬申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：計(jì)算機(jī)軟件與理論指導(dǎo)教師：周英飚20060401AbstractInthedatabasesystemthespeedofqueryprocessingaffectthelifeofapplicationsystemallkindsofDBMSattachgreatimptanceofqueryoptimization.Joinasrelational

2、databasemodel’sbasicoperationisusedmuchwhichoperatesondifferentrelationsthecostofexecutionislarge.Sothekeyofqueryoptimizationisoptimizationofmultijoinquery.Thispaperwilloptimizetheprocessingofjoinquerybasedonjoinindex.Th

3、ediscussionontheoptimizationofmultijoinqueryisusuallyaboutthederofjoinwhichfirstexecutesthejoincostminimum.Thispaperwillneglectthissectionfocusontheoptimizationofjoinoperationnamelytheimprovementofjoinalgithm.Thealgithmb

4、asedonjoinindextakesuseoftheprejoininfmationintheindextooptimizethequery.Thejoinindexwillcostmuchfmaintenancebecauseitisgeneratedbytheprejoinbuiltonmultiplerelations.FconsiderationofaffectiontothewholeDBMSintheconditiono

5、fcomplexquerythealgithmhasbeenoptimizedbasedontheanalysiscamparionofthetraditionaljoinindexalgithm.Fthereasonofthenoderofspacedatathealgithmbasedonjoinindexhavetoimprovefit.Thekeyproblemofoptimalpageaccesssequencewithafi

6、xedBufferhasbeenanalyzed.Onthebasisoftraditionaljoinalgithmthispaperimplementsanoptimizedalgithm.Theimprovedalgithmshouldperfmbetterbecauseitusesbestofallocatedmemyonlyscansthepartsofrelationwhichwillproducethejoinresult

7、avoidmostredundantIO.Allkindsofelementwhichwouldaffecttheperfmanceofalgithmhavebeenconsideredintheexperiment.theexperimentaldataindifferentconditionshasbeenusedtotesttheperfmanceofalgithmsinthesystemfthevalidationofthepo