Expert Instructor Insights: Using the Recovery Catalog in Oracle Database 11g and 12c

Source: The OFFICIAL Home Blog of Oracle University Training & Certification

By Adriana Garjoaba-Oracle on Apr 04, 2016 / Written by Bill Millar and Steve Jones, Oracle University

Expert Instructor Insights: Using the Recovery Catalog in Oracle Database 11g and 12c

For backup and recovery in Oracle Database 11g and Oracle Database12c, the recovery catalog is one of the available technologies.

Oracle University recently presented a webinar, Oracle Database 11g and 12c Backup and Recovery Strategies, that explains why we use a recovery catalog, as well as other backup and recovery technologies. Here are some highlights.

One of the greatest benefits of the recovery catalog is its ability to provide a level of protection.

The repository that contains RMAN metadata about backups by default resides in the control file. The recovery catalog acts like a replica of what's in our control file, but it also provides a lot more history and content, which is useful if we need to retain that metadata over a long period of time.

If we lose our control file and have lost that metadata, do we have that metadata in tact in my recovery catalog? If so, that's a great protection level.

Metadata

• Database structure
• Archived redo logs
• Backup sets
• Data file copies

A recovery catalog offers a number of advantages. We've got historical metadata, and the ability to store scripts. We can run custom reports against one or more registered targets.

We have the ability to override our retention policy from the backup, and specify KEEP FOREVER. We can list metadata for different content and different time periods.

And if we lose our control files, the recovery catalog is our backup.

Benefits of Using Recovery Catalog

• Stores more additional historical metadata than the control file
• Lets you use RMAN stored scripts
• Lets you create customized reports for all registered targets
• Lets you use the KEEP FOREVER clause of the BACKUP command
• Allows you to list metadata of the data files and tablespaces that were in the target database at a given time
• Simplifies restore and recovery following the loss of the control file - it preserves RMAN repository metadata

How do you set up a recovery catalog?

1. Configure the recovery catalog database.
2. Create the tablespace to contain objects.
3. Create the recovery catalog owner with recovery_catalog_owner role.
4. Create the recovery catalog.

How large is that the tablespace?

That depends on the number of databases for which we’re going to house metadata. Once we have a tablespace created, we create the schema owner of the recovery catalog objects.

We point to the tablespace that we just created, and grant an UNLIMITED QUOTA on that tablespace, and a recovery_catalog_owner role to the user that will own the recovery catalog objects. The recovery catalog owner will connect and issue the ‘create catalog’ command, resulting in the objects being created.

Once we've got the recovery catalog objects created, all of our target databases need to be registered.

As we register those databases, we're going populate the RMAN metadata into the recovery catalog objects. We also copy structure information into the recovery catalog objects for each and every one of those databases.

We connect to both the target database and, concurrently, to the catalog schema, and issue the command REGISTER DATABASE. We can use the command line method of registering all of those target databases. Or we can register the database through Oracle Enterprise Manager.

We can treat our recovery catalog as we would any production target. Of course, we need to think about a backup strategy for the recovery catalog because it's a separate database, too. We can back up to tape or disk.

We can use RMAN for those backups. We can use Data Pump for a logical backup. It is suggested to periodically backup the recovery catalog to include datafiles, control files, Server Parameter File along with archivelogs if running in archivelog mode.

View the full webinar, Oracle Database 11g and 12c Backup and Recovery Strategies, to learn more about the recovery catalog and other related technologies.

For more related training and certification exams, check out the list below:

Oracle Database 11g

• Oracle Database 11g Administrator Certified Professional
• Oracle Database 11g: Administration Workshop I Release 2
• Oracle Database 11g: Administration Workshop II Release 2

Oracle Database 12c

• Oracle Database 12c Administrator Certified Professional
• Oracle Database 12c: Administration Workshop Ed 2
• Oracle Database 12c: Backup and Recovery Workshop Ed 2
• Oracle Database 12c: Managing Multitenant Architecture
• Using Oracle Enterprise Manager Cloud Control 12c Ed 2