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DBA - Whole Database Backup and Partial Database Backup

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• DBA - Whole Database Backup and Partial Database Backup
  • Whole Database Backup
    • Command
    • Lab: Creating a Whole Database Backup
    • Lab: Back up the database and archive logs as image copies.
  • Partial Database Backup
    • Backup Pluggable Database
      • Connect with CDB
      • Lab: Backup Pluggable Database in CDB root
      • Connect with PDB
      • Lab: Backup Pluggable Database in PDB
    • Backup Tablespace
      • Connect with CDB
      • Lab: Back up the tablespace in CDB
      • Connect with PDB
      • Lab: Back up the tablespace in PDB

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Whole Database Backup

• Whole Database Backup:

  • a copy of all data files and the control file.
  • Back up all PDBs datafiles and CDB root files.

• Prerequisites

  • target database is mounted or opened.不必须打开数据.

• Steps:

  • start RMAN and connect to the target database.
  • use BACKUP command

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Command

Command	Backup Description	Storage
BACKUP DATABASE;	DF, CF	backup set
BACKUP COPY OF DATABASE;	DF, CF	image copies
BACKUP DATABASE PLUS ARCHIVELOG;	DF,CF,ARLF	backup set
BACKUP AS COPY DATABASE PLUS ARCHIVELOG;	DF,CF,ARLF	image copies
BACKUP DATABASE PLUS ARCHIVELOG DELETE INPUT;	DF,CF,ARLF, remove ARLF	backup set

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Lab: Creating a Whole Database Backup

-- rman

-- View the structure of the CDB in terms of PDBs, tablespaces, and data files (permanent and temporary).
REPORT schema;
-- Back up the whole database.
BACKUP DATABASE;
-- List the backup sets.
LIST BACKUP;

• Backup of Control file and Spfile

• The operation creates multiple backup sets.

• Verify that the files are stored on disk in the FRA.

cd /u01/app/oracle/fast_recovery_area/ORCL
ls -ltR

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Takw-away:

• As long as the database is in ARCHIVELOG mode, the backup can take place while the database is opened. This is a hot backup (or online backup).

  • Online backups are inconsistent because with the database opened, there is no guarantee that the data files are synchronized with the control files.

• If the database is in NOARCHIVELOG mode, it requires the database is closed. This is a cold backup (or offline backup).

  • offline backups taken while the database is not opened are consistent because, at the time of the backup, the system change number (SCN) in data file headers matches the SCN in the control files.

• Question: How can hot backups (inconsistent backups) be used in complete database recovery?

  • During a complete recovery, restored online backups are recovered until the current SCN is matched, with the use of the archive log files and online redo log files.
  • 即online backups + archive log files + oneline redo log files = complete recovery

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Lab: Back up the database and archive logs as image copies.

-- rman

BACKUP AS COPY DATABASE PLUS ARCHIVELOG DELETE INPUT;
-- order:
--    archived log copy
--    delete archived log copy
--    datafile copy
--    SPFILE backup set
--    archived log copy
--    delete archived log copy

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• Troubleshooting

• solution:
  • Increase the DBE_RECOVERY_FILE_DEST_SIZE parameter value

ALTER SYSTEM SET db_recovery file dest size = 30G SCOPE=both;

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Partial Database Backup

• Partial CDB Backup

  • Back up the CDB root and/or individual PDBs.
  • including:
    • the entire set of datafiles of the CDB root,
    • all datafiles of defined PDBs,
    • and the control file and SPFILE (configured to be backed up automatically)

• Autobackup is also valid for partial backups.

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Backup Pluggable Database

Connect with CDB

rman TARGET /

-- backup all datafiles in the CDB$root, including system, sysaux, undo, users
BACKUP PLUGGABLE DATABASE "CDB$ROOT";   -- quotation is needed

-- backup all datafiles in
BACKUP PLUGGABLE DATABASE pdb1;

-- backup all datafiles in Both CDB$root and pdb1
BACKUP PLUGGABLE DATABASE "CDB$ROOT", pdb1;

-- backup both CDB$root and pdb1 and archive log
BACKUP PLUGGABLE DATABASE "CDB$ROOT", pdb1 PLUS ARCHIVELOG;

When in CDB, backing up the archivelog with PDB is allowed.

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Lab: Backup Pluggable Database in CDB root

-- rman
rman target /

BACKUP PLUGGABLE DATABASE pdb1 PLUS ARCHIVELOG;

• How many backup sets are created?
  • Four backup sets:
    • one for the PDB data files,
    • one for the SPFILE and control file,
    • one for the archived log files before the data file backup set,
    • and one for the archived log files after the data file backup set.

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Connect with PDB

• Backup PDB

rman TARGET username@pdb

-- backup all df within the current pdb only
BACKUP DATABASE;

-- Do the same
BACKUP PLUGGABLE DATABASE pdb1;

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Lab: Backup Pluggable Database in PDB

-- Connect with pdb
rman target SYS@pdbl

-- backup current pdb
BACKUP DATABASE;

Notice that the SPFILE and control file are - not backed up.

• Backup outside of the current pdb is not allowed

• Backup archivelog is not allowed

• Try to configure the recovery setting for the PDB so that the SPFILE and control file
  • get an error message because you must be connected to the CDB root to configure any recovery settings.

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Backup Tablespace

Connect with CDB

rman TARGET /

-- Show the names of all data files (permanent and temporary) and tablespaces
REPORT SCHEMA;

-- Backup a tbsp in a pdb
BACKUP TABLESPACE pdb1:users;

-- Backup multiple tbsp in different pdbs
-- if one of the identifiers is not correct, all backup will fail.
BACKUP TABLESPACE pdb1:system, orclpdb:sysaux;

-- Without pdb name: backup the tbsp within the CDB$ROOT
BACKUP TABLESPACE SYSTEM, orclpdb:users, SYSAUX;
-- order:
--    tbsp of current pdb
--    cf, spf
--    tbsp of other pdb

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Lab: Back up the tablespace in CDB

rman target /

BACKUP TABLESPACE pdb1:users;

SPFILE and control file are autobackup

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Connect with PDB

-- connect with pdb
rman TARGET "'backupadmin@pdb1 as sysdba'"

-- Report schema in current pdb
REPORT SCHEMA;

-- Backup a tbsp in current a pdb
BACKUP TABLESPACE pdb1:users;

-- the pdb name can be ignore
BACKUP TABLESPACE system,users;

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Lab: Back up the tablespace in PDB

rman target SYS@pdb1

BACKUP TABLESPACE users;

SPFILE and Control file is not autobackup.

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