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:

1. USEFLASHBACK DATABASE TO statement specifies the point in time to be restored to.
2. If necessary, specify other options, such as RESTORE POINTS or START WITH.
3. Run this statement to start the flashback process.

Flashback Table

To flash back the table, you can use the following steps:

1. USEFLASHBACK TABLE statement specifies the table to be restored.
2. Specify the time point to be restored to, using the TO TIMESTAMP or AS OF clause.
3. If necessary, specify other options, such as RESTORE POINTS or ROW MOVEMENT.
4. Run this statement to start the flashback process.

Flashback Example

Flashback Database:

<code class="oracle">FLASHBACK DATABASE TO TIMESTAMP '2023-05-12 14:30:00';</code>

Flashback Table:

<code class="oracle">FLASHBACK TABLE employees TO TIMESTAMP '2023-05-12 12:00:00';</code>

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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