《oracle数据库恢复》PPT课件.ppt

User-ManagedCompleteRecovery,Objectives,Aftercompletingthislesson,youshouldbeabletodothefollowing:DescribemediarecoveryPerformrecoveryinNoarchivelogmodePerformcompleterecoveryinArchivelogmodeRestoredatafilestodifferentlocationsRelocateandrecoveratablespacebyusingarchivedredologfilesDescriberead-onlytablespacerecovery,MediaRecovery,UsedtorecoveralostordamagedcurrentdatafileorcontrolfileRequiresexplicitinvocationOperatesasfollows:FilesarerestoredfrombackupsRedodataisappliedtotherestoredfilesfromarchivedredologfilesandonlineredologs,OnlineRedolog,RecoverySteps,Restoreddatafiles,Databasecontainingcommittedanduncommittedtransactions,Recovereddatabase,Redoapplied,Undoapplied,5,4,3,2,1,ArchivedRedolog,RestorationandDatafileMediaRecoverywithUser-ManagedProcedures,RestorefilesusingoperatingsystemcommandsRecoverfilesusingtheSQL*PlusRECOVERcommand,ArchivelogandNoarchivelogModes,Instance,SGA,Redologbuffer,Databuffer,Largepool,Locks,Sharedpool,Datadict.cache,SharedSQLandPL/SQL,ARCn,Userprocess,Serverprocess,PGA,Userprocess,Serverprocess,PGA,Database,Parameterfile,Passwordfile,RecoveryinNoarchivelogMode,InNoarchivelogmode,youmustrestorethefollowingdatabasefiles:DatafilesControlfilesYoumayalsorestorethefollowingfiles:RedologfilesPasswordfileParameterfile,RecoveryinNoarchivelogMode,AdvantagesEasytoperform,withlowriskoferrorRecoverytimeisthetimeittakestorestoreallfiles.DisadvantagesDataislostandmustbereappliedmanually.Theentiredatabaseisrestoredtothepointofthelastwholeclosedbackup.,PasswordFile,ParameterFile,PasswordFile,ParameterFile,Datafile3,RedologFile2,DataFile2,ControlFiles,RedologFile1,Datafile1,Database,145,146,146,146,146,146,RecoveryinNoarchivelogModeWithRedoLogFileBackups,Backup,Restorefromthemostrecentbackup,Database,PasswordFile,ParameterFile,RecoveryinNoarchivelogModeWithoutRedoLogFileBackups,1.Shutdowntheinstance.2.Restorethedatafilesandthecontrolfilefromthemostrecentwholedatabasebackup.3.Performcancel-basedrecovery.4.OpenthedatabasewiththeRESETLOGSoption.,RecoveryinArchivelogMode,CompleteRecoveryUsesredodataorincrementalbackupsUpdatesthedatabasetothemostcurrentpointintimeAppliesallredochangesIncompleteRecoveryUsesbackupandredologstoproduceanoncurrentversionofthedatabase,CompleteRecovery,Makesurethatdatafilesforrestoreareoffline.Restoreonlylostordamageddatafiles.Donotrestorethecontrolfiles,redologfiles,passwordfiles,orparameterfiles.Recoverthedatafiles.,CompleteRecoveryinArchivelogMode,AdvantagesOnlyneedtorestorelostfilesRecoversalldatatothetimeoffailureRecoverytimeisthetimeittakestorestorelostfilesandapplyallarchivedlogfilesDisadvantagesMusthaveallarchivedlogfilessincethebackupfromwhichyouarerestoring,DeterminingWhichFilesNeedRecovery,ViewV$RECOVER_FILEtodeterminewhichdatafilesneedrecoveryViewV$ARCHIVED_LOGforalistofallarchivedredologfilesforthedatabaseViewV$RECOVERY_LOGforalistofallarchivedredologfilesrequiredforrecovery,User-ManagedRecoveryProcedures:RECOVERCommand,SQLRECOVERDATABASE;ORSQLRECOVERDATAFILE2/ORADATA/u03/users01.dbf;,Recoveramounteddatabase:,SQLRECOVERTABLESPACEusers;ORSQLRECOVERDATAFILE3;,Recoveranopendatabase:,UsingArchivedRedoLogFilesDuringRecovery,Tochangearchivelocation,usetheALTERSYSTEMARCHIVELOGmand.Toapplyredologfilesautomatically:IssuetheSETAUTORECOVERYONcommandbeforestartingmediarecoveryEnterautowhenpromptedforanarchivedlogfileUsetheRECOVERAUTOMATICmand.,RestoringDatafilestoaNewLocationwithUser-ManagedProcedures,Useoperatingsystemcommandstorestorethedatafiletothenewlocation.UsetheALTERDATABASERENAMEFILEcommandtorecordthechangeinthecontrolfile.,CompleteRecoveryMethods,Closeddatabaserecoveryfor:SystemdatafilesUndosegmentdatafilesWholedatabaseOpendatabaserecovery,withdatabaseinitiallyopened(forfileloss)Opendatabaserecoverywithdatabaseinitiallyclosed(forhardwarefailure)Datafilerecoverywithnodatafilebackup,CompleteRecoveryofaClosedDatabase,Closeddatabaserecoveryisusedfor:SystemtablespacedatafilesRollbacksegmentdatafilesWholedatabase,Shutdowntheinstance,1,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,ClosedDatabase,Archivedlogfile,144,ClosedDatabaseRecoveryExample,Restoredatafile1(LogSequence144),2,Openthedatabase,4,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,MountedDatabase,3,Datafile3,Redologfile2,Controlfiles,Redologfile1,Datafile1,RecoveredDatabase,146,145,146,146,146,Datafile2,146,3,3,OpenDatabaseRecoveryWhentheDatabaseIsInitiallyOpen,Usethismethodwhen:ThedatabaseiscurrentlyopenThedatabasewillremainopenduringtherecoveryThemediafailuredoesnotaffecttheSYSTEMtablespace,1,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,OpenDatabaseRecoveryExample,2,4,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,146,145,146,144,146,146,3,3,3,Datafile3,Redologfile2,Controlfiles,Redologfile1,Datafile1,146,145,146,146,146,Datafile2,146,Takedatafile2offline,Restoredatafile2(LogSequence144),Bringdatafile2online,Archivedlogfile,144,OpenDatabase,OpenDatabase,RecoveredDatabase,OpenDatabaseRecoveryWhentheDatabaseIsInitiallyClosed,Usethismethodwhen:ThedatabaseiscurrentlyclosedThedatabasewillbeopenedduringrecoveryThemediafailuredoesnotaffecttheSYSTEMtablespace,Takedatafile2offline,2,OpenDatabaseRecoveryExample,Restoredatafile2,4,Bringdatafile2online,6,1,Mountthedatabase,3,Openthedatabase,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,Datafile3,Redologfile2,Controlfiles,Redologfile1,Datafile1,146,145,146,146,146,Datafile2,146,ClosedDatabase,RecoveredDatabase,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,146,145,146,144,146,146,5,5,5,Archivedlogfile,144,OpenDatabase,RecoveryofaDatafileWithoutaBackup,DatafileislostthatwasneverbackedupCannotbeusedwhenitisafilefromtheSYSTEMtablespace,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,146,145,146,146,146,146,OpenDatabase,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,146,145,146,144,146,146,Archivedlogfile,144,OpenDatabase,RecoveryWithoutaBackupExample,Bringthedatafileortablespaceonline,4,1,Takethedatafileortablespaceoffline,2,Re-createthedatafile,Datafile4,3,3,3,Datafile4,146,Datafile3,Redologfile2,Datafile2,Controlfiles,Redologfile1,Datafile1,146,145,146,146,146,146,RecoveredDatabase,Datafile4,146,Read-OnlyTablespaceRecovery,Backup2,Recovery,Case1,Case2,Case3,Backup1,Read-Only,Read-Write,Read-Only,Read-Only,Read-Write,Read-OnlyTablespaceRecoveryIssues,Specialconsiderationsmustbetakenforread-onlytablespaceswhen:Re-creatingacontrolfileRenamingdatafilesUsingabackupcontrolfile,LossofControlFiles,Youmayneedtocreatecontrol