How can the Oracle database be backed up?
There are several ways to back up an Oracle database.
- Physical backup: Physical backup involves directly copying the data files and control files of a database to a backup medium. Oracle provides tools such as RMAN (Recovery Manager) for performing physical backups.
- Back up the entire database using RMAN: RMAN allows you to back up the entire database with the full backup command BACKUP DATABASE.
- Using RMAN for incremental backup: RMAN also supports incremental backup, which allows you to use the command BACKUP INCREMENTAL to backup only the changed data blocks.
- Logical backup: A logical backup involves exporting the logical structures within a database (such as tables, views, stored procedures, etc.) for backup purposes. Tools like expdp (Data Pump) provided by Oracle can be used for logical backups.
- Perform a full database backup using expdp: expdp can be used with the FULL=Y command to back up the entire database.
- Backup at table level using expdp: expdp also supports table-level backup, which can be done by using the command EXPORT TABLES to backup specific tables.
- Archived log backups: Oracle database archived logs are used to record all changes made to the database, including inserts, updates, and deletes. RMAN can be used to back up the archived logs.
- Back up archived logs using RMAN: you can use the command BACKUP ARCHIVELOG ALL to backup all archived logs.
The choice of backup depends on the needs and size of the database. Physical backup is suitable for large databases because it allows for faster recovery. Logical backup is suitable for small databases or scenarios where only partial recovery is needed. Archive log backups can be used for incremental backups or as a supplement to other backup methods. Regardless of the backup method chosen, it is important to store backup data in reliable media and regularly test and verify the integrity and recoverability of the backups.
