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1、数据库技术的前沿ThefrontiersofdatabasetechnologyAdistributeddatabaseAdistributeddatabaseiscomposedofasetofdata,thedataonthephysicaldistributionindifferentnodesofthecomputernetwork(alsocalledareaoronsite),logicallybelongstothesamesystem.Uniikecentralizeddatabase,thereshouldbeappropriateredundancyindist
2、ributeddatabasetosuitthecharacteristicsofdistributedprocessing,andimprovetheefficiencyandreliabilityofsystemprocessing・Therefore,datareplicationtechnologyisanimportanttechniquefordistributeddatabases・Butthiskindofdataredundancyindistributeddatabaseistransparenttotheuser,theuserdoesnothavetokno
3、wtheexistenceoftheredundantdata,maintaintheconsistencyofeachcopyshallbetheresponsibilityofthesystem・Distributeddatabasesareacombinationofdatabasetechnologyanddistributedprocessingtechnologies・Duetothedevelopmentofcomputertechnologyandsomegeographicallydispersedmanagementoffinancial,business,gr
4、oup,companyrequirementsontheapplicationofthedatabase,databasemanagementsystemrunningenvironmentfromonemachinetothenetwork,totheprocessingofdatafromcentralizedtodistributed,fromclosedtoopen,distributeddatabasearisesatthehistoricmoment・Datainthedistributeddatabasesystemisdistributed,datadistribu
5、tionindifferentnodesofthecomputernetwork,andthesedataarelogicallyawhole,constitutealogicaldatabase・Eachnodeinthenetworkhastheabilitytoindependentlyhandiethedatainthelocaldatabase,aswe11astostoreandprocessdatainaremotedatabase・Suchasbanktransfer,abranchoftheaccountintheamounttransferredtoanothe
6、rbranchofaccount,namelydatabasetransferfromonenodetoanothernodedatabase,needtoupdatetwonodesofthedatabaseatthesametime・Thisisthedataprocessingofthelocaldatabaseandthedataprocessingoftheremotedatabase・Asgeographicallydispersedusersdemandfordatabasesharing,incombinationwiththedevelopmentofcomput
7、ernetworktechnology,thetraditionalcentralizeddatabasesystembasedontheproductionandthedevelopmentofthedistributeddatabasesystem.Distributeddatabasesshouldhavethefollowingcharacteristics・(1)thephysicaldistributionofdata・?????Thedatainthed
