| Is your Oracle database inaccessible due to | | | | to start up your database with damaged public rollback |
| corruption? Are you unable to open a corrupt | | | | segments. You can use this undocumented parameter |
| database and extract information from it? You may | | | | without concerning about invalidating support. |
| face critical situations, if you are an Oracle data base | | | | _allow_read_only_corruption- It enables the database |
| administrator. Being a database administrator, it is a big | | | | to be accessed even if it is corrupt. You should use |
| responsibility on you to keep your database up to date | | | | this option only while exporting as much information |
| and running. Database corruption leads to severe data | | | | from your damaged Oracle database as possible |
| loss and affects working of entire organization. In such | | | | before you re-create the database. You must not use |
| critical situations, you must restore the data from | | | | the database in normal manner, which is opened in this |
| current backup to fix the issue. But if backup is not | | | | manner. |
| available, Oracle database recovery becomes need of | | | | _corrupt_blocks_on_stuck_recovery - You can use |
| hour. | | | | this database to start your damaged database. But, it |
| You must keep in mind that in case of emergency, | | | | is possibly not supported if you do it without blessing of |
| you can open your corrupt database and access | | | | Oracle. You should immediately expert database |
| some data from it. It is possible using some special | | | | tables in such cases and rebuild it. |
| hidden parameters. This database corruption generally | | | | You should use the above hidden parameters to |
| occurs due to database block corruption. Such hidden | | | | recover database only in case of emergency. The |
| parameters enable you to easily ignore the damaged | | | | must be used by taking help from technical support of |
| data blocks if the database is severely damaged. | | | | Oracle as improper use of these hidden parameters |
| Some of the hidden parameters of the database are | | | | can cause further data loss. |
| as given below: | | | | In such cases, You need to repair Oracle database |
| _allow_resetlogs_corruption- This parameters is the | | | | using third-party applications. They use most efficient |
| only method to initialize 'db backed-up open without | | | | scanning methods to ensure absolute recovery. Such |
| setting backup' on the tablespace. It makes your | | | | database repair software are completely safe and |
| system unsupported. | | | | easy to use. |
| _corrupted_rollback_segments- It is the only method | | | | |