How to recover accidentally deleted oracle table data

Oracle provides the following data recovery methods: Rollback segment: suitable for table deletion outside the automatic commit mode, use the ROLLBACK command. Flashback query: Query past table versions, requires flashback logging to be enabled, and uses SELECT syntax. Table space point-in-time recovery: Applicable to table spaces with this feature enabled, using standby copies and point-in-time recovery. Restore from backup: Restore the backup and import the restored tables, requiring a backup to be available.

How to recover accidentally deleted Oracle table data

Oracle provides a variety of methods to recover accidentally deleted tables data. Choosing the best method for your situation depends on your backup strategy and the importance of your data.

Using Rollback Segment

• If the table is accidentally deleted, but the database is using auto-commit mode, you cannot use the rollback segment to Data recovery.
• If the database is using manual commit mode, you can perform the following steps:

1. Use the ROLLBACK command to roll back all transactions to before the delete occurred .
2. Use the SELECT command to check whether the table data has been restored.

Using Flashback Query

• Flashback Query allows you to query past versions of a table.
• This method can be used as long as flashback logging is enabled.
• Use the following syntax to perform a flashback query:

<code class="sql">SELECT * FROM TABLENAME AS OF TIMESTAMP 'timestamp';</code>

where timestamp is the time when the data was deleted.

Using Tablespace Point-in-Time Recovery

• This method allows you to recover a tablespace to a specific point in time.
• This method can be used as long as table space point timely recovery is enabled.
• Use the following steps to perform a point-in-time recovery of a table space:

1. Create a standby copy of the table space.
2. Restore the standby copy to the point in time before the deletion occurred.
3. Switch the table space to the standby copy.
4. Use the SELECT command to check whether the table data has been restored.

Restore from backup

• If you have a backup of the table, you can use the backup to restore the data.
• Use the following steps to restore the table from a backup:

1. Restore the backup to a test environment.
2. Verify whether the recovery is successful.
3. Import the restored table into the production environment.

Notes

• Always test in a test environment before performing recovery operations.
• If you are unable to recover your data using any of the above methods, you may need to contact Oracle Support.
• Back up your database regularly to prevent data loss.

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