How can I recover deleted data in Oracle?
To recover deleted data, you can try the following methods:
- Utilize rollback segments: If the database is configured with rollback segments, you can use them to recover deleted data. By querying the rollback segment logs, you can restore the deleted data.
- Flashback query is a feature provided by Oracle that allows users to query past data within a specific time frame. You can use SQL statements similar to the following to query deleted data.
- Retrieve all the data from the table named table_name as of one hour ago from the current timestamp.
- This will allow you to retrieve data from the past hour.
- By utilizing the Flashback Table feature in the database, one can quickly recover deleted data by using the following statement to flash back the table to its state before deletion.
- Restore table table_name to its state before it was dropped.
- This can restore the deleted table to its state before deletion.
- Backup and restore: If a database has been backed up, you can use the backup file to restore deleted data. Oracle’s recovery tools (such as RMAN) can be used to restore the backup file.
It should be noted that the above methods can only recover deleted data under specific conditions. If no backup has been made or relevant features are not enabled, it may not be possible to recover deleted data. Therefore, before deleting data, it is best to backup the database so that it can be restored if needed.
