How to flashback in oracle
Oracle Flashback allows the recovery of a database or table to a point in time in the past without the need for a full recovery. The flashback database can be restored by specifying the time point with the FLASHBACK DATABASE statement; the flashback table can be restored by specifying the time point and table name with the FLASHBACK TABLE statement. Important: Applicable only to databases with flashback logging enabled, committed transactions are recovered and subsequent changes will be lost after recovery.
Introduction to Oracle Flashback
Flashback is a powerful feature in Oracle that allows users to restore the database to a point in time in the past without having to recover or restore the entire database.
How to use Flashback
There are two main ways to perform Flashback:
- Flashback Database: Recover the entire database to a specific point in time.
- Flashback table: Restore only a single table to a specific point in time.
Flashback Database
To flashback the database, you can use the following steps:
- USEFLASHBACK DATABASE TO statement specifies the point in time to be restored to.
- If necessary, specify other options, such as RESTORE POINTS or START WITH.
- Run this statement to start the flashback process.
Flashback Table
To flash back the table, you can use the following steps:
- USEFLASHBACK TABLE statement specifies the table to be restored.
- Specify the time point to be restored to, using the TO TIMESTAMP or AS OF clause.
- If necessary, specify other options, such as RESTORE POINTS or ROW MOVEMENT.
- Run this statement to start the flashback process.
Flashback Example
Flashback Database:
FLASHBACK DATABASE TO TIMESTAMP '2023-05-12 14:30:00';
Flashback Table:
FLASHBACK TABLE employees TO TIMESTAMP '2023-05-12 12:00:00';
Note
- Flashback only applies to databases with flashback logging enabled.
- Flashback can be time consuming depending on the amount of data being recovered.
- Flashback can only restore committed transactions.
- After flashback, all changes performed after the flashback time point will be lost.
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