Oracle database corruption is very tricky, and Oracle provides several tools and tricks for opening a corrupt database.  THESE TECHNIQUES SHOULD ONLY BE ATTEMPTED WITH THE ASSISTANCE OF ORACLE TECHNICAL SUPPORT.

 

Use DUL - This is a tool to read the raw Oracle data files.  You can get (DUL) from Oracle Technical support, or your CSR

 

For immediate Oracle Corruption support, call BC.  After we have processed your credit card retainer, we can assist with any Oracle data corruption issue.

 

Undocumented Oracle recovery parameters

 

Oracle technical support has several parameters to allow them to open your database in case of data corruption.

_ALLOW_RESETLOGS_CORRUPTION. May be only way to start a db backed-up open without setting backup on tablespaces; will result in unsupported system. See detailed section on using _allow_resetlogs_corruption which follows..

_CORRUPTED_ROLLBACK_SEGMENTS. Only way to start up with corrupted public rollback segments. Can be used without fear of desupport.

_ALLOW_READ_ONLY_CORRUPTION. Allows you to open a database even if it has corruption. This should only be used to export as much data from a corrupted database as is possible before re-creating a database. You should not use a database for normal use that has been opened in this manner, as it will not be supported.

_CORRUPT_BLOCKS_ON_STUCK_RECOVERY. Can sometimes get a corrupted db up; you probably won't be supported if done without Oracle support’s blessing. Immediately export the tables you need and rebuild the db if used.

_ALWAYS_STAR_TRANSFORMATION. Helps to tune data warehouse queries if you have a properly designed data warehouse.

_SMALL_TABLE_THRESHOLD. Sets the size of table considered a small table. A small table is automatically pinned into the buffers when queried. Defaults to 2 percent in Oracle9i.