Database Reference
In-Depth Information
Recovery Manager allows you to take backups of all important components of the database, including data files, the
control file, server parameter file etc. The Oracle binaries and log files such as the diagnostic destination, audit files, and
Data Pump dump files are not backed up by RMAN. You need to request a standard file system backup for these files.
Recovery Manager has been enhanced to allow backups of individual Pluggable Databases, the root database and
the whole CDB. In the author's opinion a PDB backup should not be part of a planned backup strategy but rather an
ad-hoc backup prior to important tasks and immediately after the PDB creation. The simple rationale behind this is
that a full recovery of a Container Database will require a restore/recovery of the CDB$ROOT followed by a restore/
recovery of all Pluggable Databases. In the heat of the battle with the outage a multi-stage recovery strategy can easily
turn out to be too complex and more importantly too time consuming. Instead the whole CDB should be backed up.
This operation is not different from any other backup of a database you have issued before.
the following examples assume that your database is in arChIveLoG mode. Where specified the use of the
Flashback database feature will be required too. please remember that activating the Flashback database feature
requires another background process to write additional data to the Flashback logs. this can have a negative effect on
performance and should only be enabled after testing or where appropriate.
Note
Backing up the whole CDB
As you read before, there are multiple ways to back up a Container Database. The most common of which is most
likely the hot backup of the database, including a backup of the controlfile—automatic or manual—followed by a
backup of archived logs. On sites with high redo-generation additional archived log backups are often scheduled.
Archive log destinations can be multiplexed, either by using multiple different and distinct file system mount points
or alternatively by sending files over the network using Redo Transport Services. A base backup for an incremental
backup of the CDB is initiated as shown here:
RMAN> backup incremental level 0 database plus archivelog;
This is exactly the same command as you have used all these years to back up a database, there is no distinction
between CDB and non-CDB when it comes to backing up everything. In the author's example the backup will go straight to
the Fast Recovery Area on disk. Following this many sites opt to back the FRA up to tape, using the backup recovery area
command in RMAN. Do not forget to review redo generation and schedule additional backups as and when needed.
Enhancements for Pluggable Databases
RMAN has seen many enhancements for Pluggable Databases, which was to be expected. This section covers the
backup command, but numerous other commands have also been extended to take the PDBs into account. To backup
up an individual PDB you need to issue the backup pluggable database command as shown in this example:
RMAN> backup pluggable database rcat_pdb;
Starting backup at 22.09.2013 17:34
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=28 device type=DISK
[...]
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00017
[...]
 
 
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