ORA-600 [6006] ORA-600 [6856]

While startup, instance terminated after ORA-600 [6006] ORA-600 [6856]
Problem Description
While starting up the instance it fails with following errors:

ORA-00600: internal error code, arguments: [6006], [1], [], [], [], [], [], []
ORA-00600: internal error code, arguments: [6856], [0], [60], [], [], []

and then SMON abnormally crashes the database instance.

Cause of the Problem
These are oracle bugs and these ORA-600 [6006] and ORA-600 [6856] bug occurred whenever undo segments are trying to rollback a failed transaction and cannot.

For error "ORA-00600: internal error code, arguments: [6006], [1], [], [], [], [], [], []" ,
Oracle is undoing an index leaf key operation. If the key is not found, ORA-00600 [6006] is logged.

For error "ORA-00600: internal error code, arguments: [6856], [0], [60], [], [], []" , SMON is trying to recover a dead transaction. But the undo application runs into an internal error (trying to delete a row that is already deleted).

Solution of the Problem

1) Review the trace files and look for the object(s) involved. If the trace file does not have a SQL statement, search on the following: "block dump header"

2) In the block header there will be a seg/obj = hex value. Convert the hex to dec and this will give you the data_object_id.

3) The alert.log may also show the affected object, for example:

ORACLE Instance ORCL (pid = 8) - Error 600 encountered while recovering transaction (9999, 36) on object 45879.

SQL>select owner, object_name from dba_objects where data_object_id = object#;

This will be the object you need to work with.


To implement the solution:

1. shutdown the oracle instance.
SQL> shut immediate

2. set event - event="10513 trace name context forever, level 2" (this event and setting disables transaction recovery which was initiated by SMON). Open the pfile and add the following line inside pfile.

event="10513 trace name context forever, level 2"

3. startup instance
SQL> startup

4.
- If the object is an index - drop and recreate.
- If the object is a table - drop / export / Create Table as Select (CTAS) to change the object ID

5. shutdown the instance
SQL> shut immediate

6. remove the event
Open the pfile and remove the event line that was added.

7. startup the instance
SQL> startup