A database administrator needs to perform various operations like performing incremental backups, identifying and resolving network issues, viewing archive log destination, error generation in alert log, etc. in order to ensure that the database always remains in a running state. However, the possibility of database corruption exists due to human mistakes, virus attacks, and hardware corruption.

Database remains unmountable in most cases after it is corrupted, further rendering to inaccessibility of all its records. In such situations, if the administrator wants to access the Oracle database records, then he/she will need to use a cold backup to restore the database. However, if the administrator has not created any backup or the backup is not sufficient to meet all his/her requirements, then he/she needs to use an advanced third-party Oracle Recovery utility to repair the database.

Let’s consider a practical case, where you, as a database administrator, perform below steps:

1.You copy your database file when your database is alive.
2. Then you update the table stored in the data file.
3. After this, you shutdown the database using ’shutdown immediate’ command and change the datafile with its ‘alive’ copy.

After this, when you try to mount your Oracle database, it does not mount. The reason is-

The fundamental reason for unmountability of the database is corruption in datafile. To prevent the corruption of datafile, you should never follow the above steps sequentially.

Resolution:

It is advisable to restore the database from a standby database in order to resolve datafile corruption and to mount your Oracle database. However, if no such database exists, then you will need to repair the database. To effectively do so, you will need to search for a commercial dbf recovery application that can repair your corrupted database.

A repair tool to recover Oracle database and to bring it back to a reusable state can be easily downloaded from the Internet. Such tools can Recover Oracle Database after any logical corruption scenario using powerful recovery algorithms. Moreover, these tools do not make any change in the original database, making them completely non-destructive in nature.

For most of the Oracle database administrators, Oracle Recovery Software is a utility that they use to recover Oracle database after all kinds of logical crashes. The tool supports recovery of Oracle 9i databases. Designed for Windows XP and 2003, the read only software leaves the original database untouched and unmodified.