OutlineIntroductionWhatisadistributedDBMSDistributedDBMSArchitectureBackgroundDistributedDatabaseDesignDatabaseIntegrationSemanticDataControlDistributedQueryProcessingMultidatabasequeryprocessingDistributedTransactionManagementDataReplicationParallelDatabaseSystemsDistributedObjectDBMSPeer-to-PeerDataManagementWebDataManagementCurrentIssues
FileSystemsprogram1datadescription1program2datadescription2program3datadescription3File1File2File3
DatabaseManagementdatabaseDBMSApplicationprogram1(withdatasemantics)Applicationprogram2(withdatasemantics)Applicationprogram3(withdatasemantics)descriptionmanipulationcontrol
MotivationDatabaseTechnologyComputerNetworksintegrationdistributionintegrationintegration≠centralizationDistributedDatabaseSystems
DistributedComputingAnumberofautonomousprocessingelements(notnecessarilyhomogeneous)thatareinterconnectedbyacomputernetworkandthatcooperateinperformingtheirassignedtasks.Whatisbeingdistributed?ProcessinglogicFunctionDataControl
WhatisaDistributedDatabaseSystem?Adistributeddatabase(DDB)isacollectionofmultiple,logicallyinterrelateddatabasesdistributedoveracomputernetwork.Adistributeddatabasemanagementsystem(D–DBMS)isthesoftwarethatmanagestheDDBandprovidesanaccessmechanismthatmakesthisdistributiontransparenttotheusers.Distributeddatabasesystem(DDBS)=DDB+D–DBMS
WhatisnotaDDBS?AtimesharingcomputersystemAlooselyortightlycoupledmultiprocessorsystemAdatabasesystemwhichresidesatoneofthenodesofanetworkofcomputers-thisisacentralizeddatabaseonanetworknode
CentralizedDBMSonaNetworkSite5Site1Site2Site3Site4CommunicationNetwork
DistributedDBMSEnvironmentSite5Site1Site2Site3Site4CommunicationNetwork
ImplicitAssumptionsDatastoredatanumberofsites?eachsitelogicallyconsistsofasingleprocessor.Processorsatdifferentsitesareinterconnectedbyacomputer