How can the data deleted in Oracle be recovered?
When using the DELETE statement in Oracle, deleted data cannot be recovered by default. Therefore, it is important to make sure that data backup is done before executing the DELETE statement.
If you want to recover deleted data without having a backup, you can try the following methods:
- With the FLASHBACK TABLE statement, you can restore deleted data after it has been removed. For example, you can use this statement to recover the table’s data to a previous point in time.
- Rewind the table named table_name to its state from one hour ago.
- This will restore data in table_name that was deleted one hour ago. Please note that this method can only be used if the database has flashback enabled.
- Database log recovery can be used to restore deleted data if the database is in ARCHIVELOG MODE. This method requires the use of Oracle’s recovery tool, such as RMAN (Recovery Manager).
- First, it is necessary to restore the database to a time point before the data was deleted, then restore the relevant tablespace or data files to the corresponding time point. Finally, use the database logs to re-import the data into the tables. This method is more complex and requires a certain level of knowledge and experience in database recovery.
- Seek help from a database administrator: If the above methods are not successful in recovering deleted data, it is best to seek assistance from a database administrator. They may try other advanced database recovery techniques or attempt to restore data from other backups.
In summary, to avoid data loss due to accidental deletion, it is recommended to back up data before deletion and regularly back up the database for data recovery when needed.
