Bypassing Oracle Corruption
For additional information
on handling corruption, see the
BC expert notes on corruption and see MOSC
Note 1088018.1 -
Handling Oracle Database Corruption Issues.
corruption is very tricky, and Oracle provides
several tools and tricks for opening a corrupt
THESE TECHNIQUES SHOULD ONLY BE
ATTEMPTED WITH THE ASSISTANCE OF ORACLE
Use DUL - This is a tool to read the raw
Oracle data files. You can get (DUL) from
MOSC or your CSR
immediate Oracle Corruption support, call
BC. After we have processed your
credit card retainer, we can assist with any
Oracle data corruption issue.
Oracle recovery parameters
support has several parameters to allow them to
open your database in case of data 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
_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.