Database Reference
In-Depth Information
Here is some sample output:
CONFIGURE SNAPSHOT CONTROLFILE NAME TO
'/ora01/app/oracle/product/12.1.0.1/db_1/dbs/snapcf_o12c.f'; # default
For most situations the default location and format of the snapshot control file are sufficient. This file doesn't use
much space or have any intensive I/O requirements. I recommend that you use the default setting.
If you have a good reason to configure the snapshot control file to a nondefault location, you can do so as follows:
RMAN> configure snapshot controlfile name to '/u01/O12C/rman/snapcf.ctl';
If you accidentally configure the snapshot control file location to a nonexistent directory, then when running a
BACKUP
or
COPY
command, the autobackup of the control file will fail, with this error:
ORA-01580: error creating control backup file...
You can set the snapshot control file back to the default, like this:
RMAN> configure snapshot controlfile name clear;
10. Using a Recovery Catalog
RMAN always stores its latest backup operations in the target database control file. You can set up an optional
recovery catalog to store metadata regarding RMAN backups. The recovery catalog is a separate schema (usually
in a database different from that of the target database) that contains database objects (tables, indexes, and so on)
that store the RMAN backup information. The recovery catalog doesn't store RMAN backup pieces—only backup
metadata.
The main advantages of using a recovery catalog are as follows:
•
Provides a secondary repository for RMAN metadata. If you lose all your control files and
backups of your control files, you can still retrieve RMAN metadata from the recovery catalog.
•
Stores RMAN metadata for a much longer period than is possible when you just use a control
file for the repository.
•
Offers access to all RMAN features. Some restore and recovery features are simpler when using
a recovery catalog.
The disadvantage of using a recovery catalog is that this is another database you have to set up, maintain, and
back up. Additionally, when you start a backup and attempt to connect to the recovery catalog, if the recovery catalog
isn't available for any reason (server down, network issues, and so on), you must decide whether you want to continue
with the backup without a recovery catalog.
You must also be aware of versioning aspects when using a recovery catalog. You need to make sure the version
of the database you use to store the recovery catalog is compatible with the version of the target database. When
you upgrade a target database, be sure the recovery catalog is upgraded (if necessary).
■
Note
See Chapter 5 for details on how to implement a recovery catalog.
