Oracle Media Recovery (media Recovery)

Official reference

https://docs.oracle.com/database/121/ADMQS/GUID-CBC5870F-2C9A-4F67-B5E9-D65049AD1E8E.htm#ADMQS09112

Translate as follows:

If you restore archived redo log files and data files, you must perform media recovery before you can open the database. Any database transactions in the archive redo log file that are not reflected in the data file will be applied to the data file, thus placing them in a transactionally consistent state before opening the database.

Media recovery requires control files, data files (typically recovered from backup), and online and archived redo log files that contain changes since the data files were made. Media recovery is typically used to recover from media failures, such as missing files or disks, or user errors, such as deleting the contents of a table.

Media recovery can be either full recovery or point-in-time recovery. A full recovery can be applied to a single data file, a tablespace, or an entire database. Point-in-time recovery applies to the entire database (sometimes also for a single tablespace with automated help from Oracle Recover Manager (RMAN)).

In full recovery, you can restore the backup data file and apply all changes in the archive and online redo log files to the data file. The database returns its status in the event of a failure and can be opened without losing data.

In point-in-time recovery, you return the database to the content of the time that was selected by the user in the past. You can restore a backup of the data files that were created before the target time and a complete set of archive redo log files from the backup creation to the target time. Recovery applies the changes between the backup time and the target time to the data file. All changes after the target time are discarded.

Rman enables you to perform full and point-in-time recovery of the database. However, this document focuses on full recovery.

"Perform user directed recovery"

For more detailed information on point-in-time recovery, see the Oracle database Backup and Recovery User Guide

Oracle Media Recovery (media Recovery)