A recovery catalog is a database schema used by RMAN to store metadata about one or more Oracle databases. Typically, you store the catalog in a dedicated database. A recovery catalog provides the following benefits:
- A recovery catalog creates redundancy for the RMAN repository stored in the control file of each target database. The recovery catalog serves as a secondary metadata repository. If the target control file and all backups are lost, then the RMAN metadata still exists in the recovery catalog.
- A recovery catalog centralizes metadata for all your target databases. Storing the metadata in a single place makes reporting and administration tasks easier to perform.
- A recovery catalog can store metadata history much longer than the control file. This capability is useful if you have to do a recovery that goes further back in time than the history in the control file. The added complexity of managing a recovery catalog database can be offset by the convenience of having the extended backup history available.
Some RMAN features function only when you use a recovery catalog. For example, you can store RMAN scripts in a recovery catalog. The chief advantage of a stored script is that it is available to any RMAN client that can connect to the target database and recovery catalog. Command files are only available if the RMAN client has access to the file system on which they are stored. A recovery catalog is required when you use RMAN in a Data Guard environment. By storing backup metadata for all primary and standby databases, the catalog enables
you to offload backup tasks to one standby database while enabling you to restore backups on other databases in the environment.