The Recovery Manager environment consists of the various applications and databases that play a role in a backup and recovery strategy.

  1. Oracle Recovery Manager (RMAN) Client: The client application that manages backup and recovery operations for a target database. The RMAN client can use Oracle Net to connect to a target database, so it can be located on any host that is connected to the target host through Oracle Net. An RMAN channel represents one stream of data to a device, and corresponds to one database server session. During a backup or restore operation, the channel reads data from the input device, processes it, and writes it to the output device. The RMAN client directs database server sessions to perform all backup and recovery tasks. What constitutes a session depends on the operating system. For example, on Linux, a server session corresponds to a server process. On Windows, a server session corresponds to a thread within the database service. The RMAN client itself does not perform backup, restore, or recovery operations. Most RMAN commands are run by channels, which must be either configured to persist across RMAN sessions, or manually allocated in each RMAN session.
  2. Target Database: A database containing the control files, data files, and optional archived redo logs that RMAN backs up or restores. RMAN uses the target database control file to gather metadata about the target database and to store information about its own operations. The work of backup and recovery is performed by server sessions running on the target database.
  3. Control File: The RMAN repository is a collection of metadata about the target databases that use RMAN for backup, recovery, and maintenance. RMAN always stores its metadata in the control file. The version of this metadata in the control file is the authoritative record of RMAN backups of a database. Therefore, an important part of your backup strategy is to protect the control file.
  4. Recovery Catalog Database: A database schema used by RMAN to store the metadata about its backup and recovery operations. A recovery catalog is a separate dedicated database and can be used to store the RMAN metadata for multiple target databases. A recovery catalog is optional because RMAN stores its metadata in the control file of each target database. However, a recovery catalog is required when you use RMAN in a Data Guard environment. The process of enrolling of a database in a recovery catalog for RMAN use is called registration. The recommended practice is to register every target database in your environment in a single recovery catalog. The recovery catalog contains metadata about RMAN operations for each registered target database. When RMAN is connected to a recovery catalog, RMAN obtains its metadata exclusively from the catalog.
    A user, within the recovery catalog database, owns the metadata tables maintained by RMAN. For RMAN operations such as backup, restore, and crosscheck, RMAN always first updates the control file and then propagates the metadata to the recovery catalog. This flow of metadata from the mounted control file to the recovery catalog, which is known as recovery catalog resynchronization or resync operation, ensures that the metadata that RMAN obtains from the control file is current.The recovery catalog database is a database like any other, and is also a key part of your backup and recovery strategy. To avoid losing metadata from disk failures that may destroy the recovery catalog database, You can use RMAN to back up the recovery catalog with the same frequency that you back up a target database. The repository for RMAN is the control file in the catalog database. Using the control file auto backup feature, you can ensure that the recovery catalog database can always be recovered, so long as the control file auto backup is available.
  5. Physical Standby Database: A copy of the primary database that is updated with redo generated by the primary database. You can fail over to the standby database if the primary database becomes inaccessible. RMAN can create, back up, or recover a standby database. Backups that you make at a physical standby database are usable at the primary database or another physical standby database for the same production database. The recovery catalog is required when you use RMAN to back up a physical standby database. Note: A logical standby database is treated as a separate database by RMAN because it has a different DBID from its primary database.
  6. Oracle SBT Libraries (Media Management Software): A vendor-specific application that enables RMAN to back up to a storage system such as tape. RMAN is preconfigured to use disk as the default device type. To create backups on non-disk media, you must use media and allocate channels supported by this software. RMAN contacts the media manager whenever the channel type allocated is not DISK. RMAN uses the Oracle Database Cloud Backup Module as the SBT interface to back up databases to OCI Object Storage, and the Oracle Secure Backup SBT interface to back up databases to tape devices.
  7. Oracle Enterprise Manager: A browser-based platform to manage Oracle Database deployments, including backup and recovery through RMAN. The RMAN client and Enterprise Manager console run on separate computers.
  8. Fast Recovery Area: A disk location that you can use to store recovery-related files such as control files, online redo log copies, archived redo logs, flashback logs, and RMAN backups. Oracle Database and RMAN manage the files in the fast recovery area automatically.