Oracle Database is one of the most reliable and secure RDBMS (Relational Database Management Systems) from Oracle Corporation. Also, this database is one of the first RDBMSs to allow the capability to read/write XML statements. The information of the Oracle database is stored in a proprietary file called the DBF (Database File) file, which sometimes get corrupt thereby disabling you from using it. But Oracle provides different methods to eradicate database corruption of varying levels. If you are unable to sort the error even after using these methods, then I would suggest you to use third-party Oracle database recovery software to recover Oracle database.
Let us have a look at few of the error messages that you may encounter either while working or while opening an Oracle database
ORA-01043: user side memory corruption
ORA-01073: fatal connection error: unrecognized call type
ORA-01053: user storage address cannot be read
ORA-01079: Oracle database was not properly created, operation aborted
The most prominent cause of these error messages is that the Oracle database has damaged. The reasons for the database corruption could be either of the ones mentioned in the introductory paragraph.
As the error messages may have occurred at different phases or user actions, there are different type of resolving methods that are provided in Oracle. Some of the most used methods are:
DBVerify: You should use this external utility to validate the offline and backup data files.
ANALYZE .. VALIDATE STRUCTURE: This command is used to check each and every block of the scanned object. If any corruption is found in the object, then the detected rows are moved to the INVALID_ROWS table.
DB_BLOCK_CHECKING: Using this method, you can set its parameter to ‘TRUE’ to check each and every block of the database object to check if it is self-consistent. This method adds about 1% to 10% overhead to the server. So, you should use this method if this much overhead is acceptable to you.
DBMS_REPAIR: This tool is actually does two tasks in a go. Unlike the previously discussed methods, it detects and repairs database corruption on its own.
You would be able to address all the errors after performing these methods. However, if this is not so then you should use third-party Oracle database recovery software. These DBF recovery tools are very safe to use that do not modify the already damaged Oracle database.
The best Oracle database recovery software, which recovers Oracle database created for Oracle 9i, 10g, and 11g versions, is Stellar Phoenix Oracle Database Recovery. Compatible with Windows Server 2003 and XP, this DBF recovery utility recovers DBF file by restoring various objects including tables, roles, views, table spaces, cluster tables, schemas, synonyms, indexes, and sequences.
Tanvi Sharma is a database recovery expert and doing research on oracle recovery software.