Databases Reference
In-Depth Information
Solution
To enable automatic control file backups, use the
autobackup
clause with the
configure
command as follows:
RMAN> configure controlfile autobackup on;
If for any reason you want to disable automatic control file backups, run the following command:
RMAN> configure controlfile autobackup off;
An alternative way to disable automatic control file backups is to clear (see Recipe 5-3 for instructions on clearing
configured RMAN settings) the auto backup setting. For example:
RMAN> configure controlfile autobackup clear;
This command will set the control file auto backup to off, which is the default setting.
How It Works
By default, automatic control file backups are disabled. Even when the auto backup feature is disabled, RMAN will
back up the current control file and the server parameter file whenever any
backup
command includes data file 1
from the data files that belong to the target database. In an Oracle database, data file 1 is always part of the system
tablespace, which contains the data dictionary. You can configure RMAN to automatically back up the control file
following
every
backup and any database structural change by using the
configure
command. We highly recommend
you configure automatic control file backups for two reasons:
•
To ensure that the critical control file is backed up regularly following a backup or structural
change to the database
•
To simplify the scripts used to back up your database
Not
■
oracle recommends you enable the control file auto backup feature if you aren't using a recovery catalog.
Once you configure automatic control file backup, RMAN will automatically back up your target database control
file, as well as the current server parameter file, when any of the following events occurs:
backup
or the
copy
command
•
Successful completion of either a
create catalog
command from the RMAN prompt is successfully completed
•
After a
•
After a
backup
or
copy
command completes and the recovery catalog—if you are using one—is successfully
updated, RMAN will then back up the control file to its own backup piece. In addition, any changes to the physical
structure of your database, even if they are made through SQL*Plus, will trigger a control file auto backup. (For
example, the following actions will trigger an auto backup of the control file: adding a tablespace or data file,
dropping a data file, placing a tablespace offline or online, adding an online redo log, and renaming a data file.)
When automatic backup is triggered by a structural change, an Oracle server process (not an RMAN process) will
automatically create the auto backup of your control file.
Any structural changes to the database modify the contents of the control file
