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Steps to perform an Open Database Backup using Oracle

The backup database command backs up all data files and the control file but not the archived redo logs. If you take a consistent backup of the database, you can later use this backup to restore and recover without performing media recovery. That is, you will not have to apply any changes from the archived redo logs before opening the database. To take a consistent backup, you must satisfy the following two conditions: You must first shut down the database normally, that is, use one of the following statements: 1) shutdown, 2) shutdown normal, 3) shutdown immediate, or 4) shutdown transactional.
  1. You must start up the database in mount state before taking the backup. If you are recovering a database using inconsistent backups, you must first make the database consistent through applying the archived redo logs before you can open it. Backups taken under the following conditions are inconsistent:
  2. If you create a backup of a database after restarting a database that was shut down abruptly (say, because of a power failure) or with the shutdown abort command
  3. If you create a backup of the database while the database is open
There is nothing wrong with inconsistent backups by definition, all open database backups are inconsistent. You can safely use inconsistent backups as the foundation of your backup and recovery strategy. Since database uptime is critical, most production databases depend on inconsistent backups. All you have to do is to make sure you are running your database in archive log mode and that you are backing up your archived redo logs along with your data files.

Steps to perform an open database backup

Note: Server Manager has been deprecated since Oracle 9i. The DBA can use 1) SQL*Plus or 2) SQL Developer instead.
The DBA must ensure the correct ORACLE_SID is set(1). From the Windows Command Prompt, the DBA starts SQL*Plus 2. User typed in to connect the database as sysdba 3. User typed the password. The default password is manager. For security reasons the user's entry is hidden (4)

The DBA ensures the database is operating in ARCHIVELOG mode (1)

DBA determines the file(s) to back up. Tablespace OEM is to be backed up. The dictionary view DBA_TABLESPACES does not show the filename (1)

The correct view is DBA_DATA_FILES which contains the file name (1).

The DBA issues a select statement to get the file name(1). The DBA must backup all files belonging to tablespace OEM. In this case there is one file to backup (2).

DBA indicates to Oracle that a backup is about to begin: Oracle freezes the file header(s). This action DOES NOT initiate a copy. The DBA must perform this action using the appropriate Operating System commands (1).

The DBA uses Server Manager's HOST command to access the Operating System (1), then copies the file to the current directory (2).

The DBA verifies the copy is present using the operating system command DIR(1)

The DBA exits from the operating system in order to return to SQL*Plus (1) and end the backup (2). Oracle updates the tablespace and datafile headers to the curent log sequence number.

DBA exits from the Operating System in order to return to the SQL*PLUS prompt (1) and end the backup (2). Oracle updates the tablespace and datafile headers to the current log sequence number.