| Are you getting "ORA-01578 runtime error" while | | | | checksum for every block before writing to the hard |
| accessing an Oracle database table? Is the table | | | | drive. |
| inaccessible and you are unable to use its data? This | | | | You can easily detect Oracle data block corruption |
| problem usually occurs if the particular table contains | | | | using an inbuilt utility, called RMAN (Oracle Recovery |
| various damaged blocks. In such cases, Oracle | | | | Manager). This tool offers you a comprehensive way |
| application cannot read the table and thus you come | | | | to effectively backup your database and recover it, in |
| across this behavior. It leads to serious data loss | | | | case of database corruption. The tools is designed to |
| situations, if you do not have a valid data backup in | | | | work with server, and detects block-level corruption |
| place. But, in case the backup is not updated, Oracle | | | | while backing up the database or restoring it. |
| database recovery is the only way to get your | | | | RMAN detects only the physically corrupt data blocks |
| mission-critical data back. | | | | on Oracle database. It does not automatically find the |
| What causes block corruption in Oracle database | | | | logical corruption of the blocks. You must specify the |
| table? | | | | logical block corruption checking using the 'CHECK |
| The block corruption can be of two types, namely | | | | LOGICAL' option. |
| logical and physical. Logical corruption may occur due | | | | In case the RMAN cannot detect logical and physical |
| to unsuccessful or improper attempts to recover a | | | | corruption to Oracle database and fix it, the database |
| database table using NOLOGGING action. It can also | | | | remains inaccessible. You encounter the same |
| be caused by virus infection and application | | | | behavior every time you try to open the database |
| malfunction. Whereas, physical corruption can be due | | | | table. It causes severe data loss and puts you in need |
| to system related problems, like damaged memory | | | | of DBF recovery solutions. |
| boards or file system structures. | | | | You can quickly and easily repair Oracle database |
| You can deal with Oracle block corruption using any of | | | | using advanced and powerful third-party applications. |
| the following initialization parameters: | | | | They employ high-end scanning methods to |
| - DB_BLOCK_CHECKING- A server process that | | | | systematically scan all corrupt Oracle database tables |
| checks data blocks for internal consistency and | | | | and extract all data from them. The applications |
| integrity. | | | | recover Oracle database in a quick, safe, and easy |
| - DB_BLOCK_CHECKSUM- It calculates the | | | | way. |