ORA-00600: internal error code, arguments: [krcrfr_nohist]

Users may see below error in alert_<SID>.log file.

Errors in file /oracle/ORAC/saptrace/diag/rdbms/ORAC/ORAC/trace/ORAC_ora_6240.trc (incident=211514):
ORA-00600: internal error code, arguments: [krcrfr_nohist], [2596956098], [49126131], [],  
ORA-00600: internal error code, arguments: [krcrfr_nohist], [2596956098], [49126131], [],
Use ADRCI or Support Workbench to package the incident.
See Note 411.1 at My Oracle Support for error and packaging details.
Fri Sep 27 21:44:47 2013
Errors in file /oracle/ORAC/saptrace/diag/rdbms/ORAC/ORAC/trace/ORAC_ora_7583.trc (incident=211585):
ORA-00600: internal error code, arguments: [krcrfi_nohist], [2596956688], [2594394265], [], [], [], [], [], [], [], [], []

Cause:
Users may see this error on databases where Block change tracking enabled. The corrupted blocks in the Block Change Tracking are causing the ORA-600 [krcrfr_nohist], which is a mismatch in the Block Change Tracking information.

This applies to Oracle 11.2.0.2 and later versions. You might be hitting a BUG:13701312 and check with Oracle Support to see any patch available.

Workaround: Disable and enable change tracking.

SQL> alter database disable block change tracking;
SQL> alter database enable block change tracking [using file '<file-name>'];

You may see below errors after ORA-00600

minact-scn: got error during useg scan e:12751 usn:1
minact-scn: useg scan erroring out with error e:12751
Suspending MMON action 'Block Cleanout Optim, Undo Segment Scan' for 82800 seconds

The above warning is raised while scanning UNDO segment. It indicates that undo segment scan has failed with ORA-12751 error.

The ora-12751 indicates that some part of MMON Operation is either taking too long to complete and taking too much CPU. Due to “Suspending MMON” you may not able to see AWR reports during the issue period.

Reference:
ORA-12751 "cpu time or run time policy violation" in the MMON Slave Process File during Feature Usage Statistics [FUS] (Doc ID 1291296.1)
Alert log shows: "Minact-scn: Useg Scan Erroring Out With Error E:12751" Warning (Doc ID 1478691.1)

Regards,
Satishbabu Gunukula, Oracle ACE
http://www.oracleracexpert.com