Summary of recovery under different Oracle database failures

Summary of recovery under different Oracle database failures
1. Files that are missing or corrupted in non-archive mode
--1.1 Data files
--Start the state of the database to mount
--Recovery method:
The entire database is repaired through a database full backup that was previously created, but any modifications that occur after the backup are lost; The recover operation is not required after the database is repaired. (because there is no archive, there is no recover), directly through the resetlogs way to open the database.

--1.2 data files and online redo log files
--Start the state of the database to mount
--recovery Method (IBID.):
The entire database is repaired through a database full backup that was previously created, but any modifications that occur after the backup are lost; The recover operation is not required after the database is repaired. (because there is no archive, there is no recover), directly through the resetlogs way to open the database.

--1.3 data files and control files
--Start the state of the database to Nomount (control file is missing or corrupt, only start database to Nomount State)
--recovery Method (IBID.):
The entire database is repaired through a database full backup that was previously created, but any modifications that occur after the backup are lost; The recover operation is not required after the database is repaired. (because there is no archive, there is no recover), directly through the resetlogs way to open the database.
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Note: In the above three cases to perform the database repair, must have the correct control file backup. Also, in the case of database recovery in these cases, the only way to open a database without using the resetlogs option is to create a full backup of the database, and the contents of the online redo log file are not overwritten. Then you should apply this part of the log through the recover operation.
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2. Files lost or corrupted in archive mode
--2.1 one or more data files
--Start the state of the database to Mount/open can be
--Recovery method:
To perform a recovery operation for a tablespace or data file while the database is open but in a loaded state, first place the tablespace or data file in the offline state, and then, by backing up Retore and recover, finally set it to the online state. This operation does not lose data, and during the operation, other data files of the database can still be accessed normally.

--2.2 All data files
--Start the state of the database to Nomount
--Recovery method
Apply the previous full-library backup for recovery, without data loss in the event that the online redo log files and archive files are still in place.

--2.3 control files and one or more data files
--Start the state of the database to Nomount
--Recovery method:
The control file is first restored through the backed-up control file, and then the database is opened to the Mount State. Restore and recover the data files, and in the case of online redo log files, this operation will not lose data.
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As long as there are control files or all data files are missing, you can only start the database to the Nomount state. In archive mode, the database does not need to be opened in open resetlogs.

Summary of recovery under different Oracle database failures