How to roll back data in oracle

Oracle data can be rolled back by using the UNDO tablespace to undo uncommitted changes. Use FLASHBACK queries to recover data at a specific point in time. Use recovery points to roll back to a known good state. Use a database backup to restore data if other methods are not available.

How to roll back Oracle data

Rolling back data in Oracle means restoring it to its previous state. It is used to undo unexpected or erroneous changes to ensure data integrity. Here are the different ways to roll back Oracle data:

1. Use UNDO tablespaces

UNDO tablespaces store copies of previous data versions, enabling you to roll back changes . Use the following query to roll back all uncommitted changes:

ROLLBACK;

2. Using FLASHBACK query

FLASHBACK query allows you to view and restore historical data at a specific point in time. To roll back to a specific point in time, use the following syntax:

FLASHBACK TABLE table_name TO TIMESTAMP (timestamp);

3. Using recovery points

Recovery points are an Oracle feature that allow you to create a database A snapshot of a known good state. To roll back to a recovery point, use the following steps:

• Create a new database session.
• Use the following query to switch to the recovery point:

ALTER SESSION SET RECOVERY_POINT = recovery_point_name;

• Roll back uncommitted changes:

ROLLBACK;

4. Use Database Backup

If you do not have an UNDO tablespace, FLASHBACK query, or recovery point, you can use a database backup to roll back the data. To restore data using a backup, use the following steps:

• Stop the database instance.
• Restore backup.
• Restart the database instance.

Note:

• Rollback will undo all uncommitted changes.
• If changes were committed before rolling back, you cannot use UNDO tablespaces or FLASHBACK queries to roll back.
• Recovery points are only retained for a limited time.
• Database backup may take a long time to restore.

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