How to recover deleted data in oracle

Oracle provides multiple mechanisms for recovering deleted data: Rollback operation: Restore to the state before deletion Restore from backup: Overwrite changes since the backup Flashback query: Query past time point data UNDO table space: Through Transaction log recovery data third-party tool: Provides advanced features and user-friendly interface

How to recover Oracle deleted data

Introduction
It is not uncommon to accidentally delete an Oracle table or data row. Oracle provides several mechanisms to recover this deleted data. This article will explore the different methods of recovering Oracle deleted data.

Method

1. Rollback operation
If the deletion operation occurred recently, you can perform a rollback operation. A rollback operation restores the database to its previous state, including deleted data.

<code>ROLLBACK;</code>

2. Restore from backup
If the database has been backed up, you can restore deleted data from the backup. The restore process will overwrite all changes made since the backup.

3. Using Flashback Query
Flashback query allows you to query data from a specific point in time in the past, even if the data has been deleted.

<code>SELECT * FROM table_name AS OF TIMESTAMP timestamp;</code>

4. Use UNDO tablespace
UNDO tablespace stores the transaction log of changes made to the database. If data is accidentally deleted, you can use an UNDO tablespace to recover it.

<code>SELECT * FROM undo_table_name WHERE rowid = original_rowid;</code>

5. Use third-party tools
There are a variety of third-party tools that can help you recover deleted Oracle data. These tools typically offer more user-friendly interfaces and more advanced functionality.

Notes

• It is very important to perform recovery in a timely manner because deleted data may be overwritten over time.
• It is recommended to always back up the database before performing recovery operations.
• If you cannot recover your deleted data, you may want to consider using a data recovery service.

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