Oracle database recovery method

Oracle database recovery methods are to use database backup recovery, flashback technology recovery, data recovery tool recovery, database reconstruction technology recovery and emergency repair (ER) mode recovery. Detailed introduction: 1. Use database backup and recovery. When the database fails, you can restore the database by using these backup sets; 2. Use flashback technology to restore the data to the most recent consistent state when the database fails. ; 3. Use data recovery tools to recover, etc.

Oracle database recovery refers to restoring the database to a normal or acceptable state through certain technologies and methods in the event of database failure or data loss. status. Oracle Database recovery mainly includes the following methods:

1. Use database backup and recovery: When performing database backup, Oracle The database creates a backup set containing the data files, archive log files, and control files. When a database failure occurs, the database can be restored by using these backup sets. The advantage of this method is that the recovery speed is fast, and the data integrity and consistency after recovery are guaranteed. can use RMAN (Oracle database backup and recovery tool) to perform backup and recovery operations.

2. Recovery using flashback technology: Oracle The database provides flashback technology, which can restore data to the most recent consistent state when the database fails. Flashback technology includes flashback query (Flashback Query), Flashback Transaction and Flashback Recovery Recovery) etc. These technologies can roll back the data to a certain point in time while the database is running, so that the data can be viewed or repaired. Flashback technology can effectively reduce problems caused by data inconsistency and improve system availability.

3. Use data recovery tools to recover: When the database fails and the data cannot be restored directly using backup or flashback technology, you can use some third-party data recovery tools, such as Oracle Database recovery tool (DBR), Stellar Data Recovery wait. These tools can scan database files to identify and recover corrupted data. However, it should be noted that when using these tools for recovery, the recovered data may not be complete and consistent and requires further inspection and repair.

4. Use database reconstruction technology to recover: When a serious failure occurs in the database, such as database file damage, table space damage, etc., you may need to use database reconstruction (Database Re-construction) technology to recover data. This method requires analysis and reconstruction of the database structure, which may require a long recovery time. When refactoring your database, you can use Oracle Database flashback technology flashes data back to an acceptable state and then reconstructs it.

5. Use emergency repair (ER) mode to recover: In Oracle database, you can also use emergency repair (ER) mode to recover data. ER A schema is a special database schema that can be used to repair damaged database files, table spaces, etc. In ER mode, you can execute some special SQL statements, such as ALTER DATABASE RECOVER FROM ERASEPOINT, etc., to recover data. However, it should be noted that when using ER mode for recovery, you need to operate with caution to avoid further damage to the database.

In short, Oracle When restoring the database, you need to choose an appropriate recovery method based on the specific circumstances of the failure. When performing recovery operations, you should try to ensure the integrity and consistency of the data to ensure that the restored database can operate normally. At the same time, in order to prevent database failures, it is recommended to perform regular database backups and monitor the database operating status so that potential problems can be discovered and dealt with in a timely manner.

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