Alter database open fails with ORA-00600 kcratr_nab_less_than_odr

Alter database open fails with ORA-00600 kcratr_nab_less_than_odr

Database Version: 11.2.0.1

Symptoms
After Power Fail Alter database open fails with
ORA-00600: internal error code, arguments: [kcratr_nab_less_than_odr]

Changes
Power failure

Cause
There was a power failure causing logical corruption in controlfile

Solution:-

Option a:

SQL>Startup mount ;

SQL>Show parameter control_files

Query 1

sql>select a.member,a.group#,b.status from v$logfile a ,v$log b where a.group#=b.group# and b.status='CURRENT'

Note down the name of the redo log

SQL>Shutdown abort ;

Take a OS Level back of the controlfile (This is to ensure we have a backup of current state of controlfile)

SQL>Startup mount ;

SQL>recover database using backup controlfile until cancel ;

Enter location of redo log shown as current in Query 1 when prompted for recovery Hit Enter

SQL>Alter database open resetlogs;

Option b:

Recreate the controlfile using the Controlfile recreation script

With database in mount stage

rman target /

rman> spool log to '/tmp/rman.log';

Rman> list backup ;

Rman > exit

Keep this log handy

Go to sqlplus

SQL> Show parameter control_files

Keep this location handy.

SQL>oradebug setmypid

SQL>Alter session set tracefile_identifier='controlfilerecreate' ;

SQL>Alter database backup controlfile to trace ;

SQL>Oradebug tracefile_name ; --> This command will give the path and name of the trace file


Go to this location ,Open this trace file and select the controlfile recreation script with NO Resetlogs option

SQL>Shutdown immediate;


Rename the existing controlfile to _old ---> This is Important as we need to have a backup of existing controlfile since we plan to recreate it

SQL>Startup nomount

Now run the Controlfile recreation script with NO Resetlogs mode

SQL>Alter database open ;

For database version 10g and above

Once database is opened you can recatalog the rman backup information present in the list /tmp/rman.log using

Rman> Catalog start with '' ;

Once the database has been opened using the option a or option b its recommended to take a hot backup of the database.
Same Steps are applicable to Rac if all instance are down with same error.