Recovery manager (RMAN) is a command line utility used to perform backup and recovery operations. RMAN provide greater ease of management and administration of the backup and recovery operations.

Benefits of recovery manager

The key objective of RMAN (recovery manager) is to provide greater ease of management and administration of the backup and recovery operations. RMAN and the oracle server minimize operational errors, by automating the backup and recovery process, and by performing multiple consistency checks throughout the procedure.

RMAN decides how to execute backup, restore, or recovery operations based on information in the database's recovery catalog, control file, and the current state of the datafiles, then instructs and coordinates oracle server processes to perform the desired operation.

CONFIGURE rman command is the configuration mechanism for RMAN envrionment. These settings (rman configuration) apply to all RMAN sessions until explicitly changed or disabled. SHOW command is use to display the rman configurations for one or more databases.

The CONFIGURE rman command always stores a rman configuration for a target database in the target database control file. If you use a recovery catalog, then RMAN also stores rman configuration settings for each registered database in the catalog.

RMAN CONNECT command establishs a connection between RMAN and a target, auxiliary, or recovery catalog database.

• RMAN CONNECT command connections to a target or auxiliary database require the SYSDBA privilege. The AS SYSDBA keywords is not required while connecting
• Use CONNECT command at the RMAN prompt and only if RMAN is not already connected to the database.
• To connect to a different target, catalog, or auxiliary database start a new RMAN session.

Following is the RMAN command list mostly used during the rman backup and recovery operations. These rman commands can be executed at RMAN prompt, or within a RUN block.

The most important rman command is RMAN BACKUP command that is used to backup database files. While RMAN RECOVER command used to recover from database failues and apply redo log files from backup to update them. Before using RECOVER command you must use RESTORE command to restor database files from backup.

The rman DUPLICATE command is another RMAN command used to create duplicate or copy database to another machine using previous backups for checking backups or testing purpose.

This article provide basic overview of oracle database backup and recovery and provide answers to some common question including:

• What are Physical and logical backups
• Oracle database failures that can occure during operation such as Media Failures, User Errors and Application Errors
• Oracle backup and recovery failure solutions such as User-managed backup and recovery, Recovery Manager (RMAN)
• What are the RMAN backup features
• Oracle flashback technology provide additional layer of data protection and provide to view past states of data and rewind your database without restoring backups.
• Data recovery advisor automatically diagnoses persistent data failures, presents appropriate repair options, and executes repairs at your request

Recovery Manager (RMAN) is an Oracle Database client that performs backup and recovery tasks on your databases and automates administration of your backup strategies. The RMAN environment consists of the utilities and databases that play a role in backing up your data. RMAN includes following components.

• Target Database
• RMAN Repository
• Recovery Catalog
• RMAN Client
• Media Manager
• Flash Recovery Area

Connecting to RMAN can be achieved by simply typing rman at the operating system prompt. some of the common operation are as follows

• Syntax of RMAN connect Command
• Connecting to RMAN without any Connection
• Connecting to RMAN With Target Database
• Connecting to RMAN With Recovery Catalog
• Connecting to RMAN Without Recovery Catalog
• Exiting RMAN

The RMAN backup and recovery environment is preconfigured for each target database. The configuration is persistent and applies to all subsequent operations on target database, even if you exit and restart RMAN.

• Showing and Clearing Default RMAN Backup Configurations
• Configure RMAN Backup Device Type: Disk or SBT
• Configure RMAN Backup Default Type for Backups: Backup Sets or Copies
• Configure RMAN Backup Channels

You can use the SHOW and CONFIGURE commands to view and change RMAN configurations.