There are times when it may become necessary to force a database open. This
document identifies one way to attempt to get the database open.
You may need to use this procedure because something happened to the database
that required you to perform recovery. The recovery completed, but you receive
the following error message:
ORA-01194 - file 1 needs more media recovery to be consistent
You have determined that there is nothing else that can be done to get the
database to a consistent state. You tried opening the database using
RESETLOGS, but that also failed.
Procedure:
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To ATTEMPT to force the database open, perform the following steps:
1. Add the parameter _ALLOW_RESETLOGS_CORRUPTION = TRUE to the init.ora file
_corrupted_rollback_segments=
2. STARTUP MOUNT the database
3. Issue the appropriate RECOVER DATABASE command:
a) RECOVER DATABASE UNTIL CANCEL
or
b) RECOVER DATABASE USING BACKUP CONTROLFILE UNTIL CANCEL
4. Enter CANCEL to cancel recovery - there are NO archive logs applied.
5. Enter ALTER DATABASE OPEN RESETLOGS
6. Try selecting from a table - for example, SELECT SYSDATE FROM DUAL
If you get a row back, the database is open and "functional" - you
could try to select from a couple of other tables just to make sure.
If the instance crashed, check for trace files in the background dump
destination. If you find a trace file, check to see if the trace file
has an ORA-00600 [2662] error in it - this may also show up in the
alert.log file. If this is true, then perform the following steps:
7. SHUTDOWN ABORT
8. STARTUP MOUNT
9. ALTER SESSION SET EVENTS '10015 TRACE NAME ADJUST_SCN LEVEL 1';
10. ALTER DATABASE OPEN
11. Trying selecting rows from a table
12. If the instance crashes again, check the trace file for another
ORA-00600 [2662] error. If so, go back to step 9 and increment the
LEVEL by 1 and repeat steps 9 through 12 until you can successfully
select rows. If you need to go beyond level 6 or 7, then the database
is probably too far gone to continue.
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* *
* CAUTION: Once the database is open, it is imperative that you export, *
* rebuild the database, and import. *
* *
* By forcing open the database in this fashion, there is a strong *
* likelihood of logical corruption, possibly affecting the data *
* dictionary. Oracle does not guarantee that all of the data will be *
* accessible nor will it support a database that has been opened by *
* this method and users allowed to continue work. All this does is *
* provide a way to get at the contents of the database for extraction, *
* usually by export. It is up to you to determine the amount of lost *
* data and to correct any logical corruption issues. *
* *
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