Windows 2008 Enterprise
After upgrade from 220.127.116.11 to 18.104.22.168 release, as part of R12 dbtier post-installation procedure, required to run adstats.sql and getting the following error
ERROR at line 1:
ORA-20011: Approximate NDV failed: ORA-00600: internal error code, arguments:
, , , , , , , , , , , 
ORA-06512: at "SYS.DBMS_STATS", line 24098
ORA-06512: at "SYS.DBMS_STATS", line 24629
ORA-06512: at line 3
ORA-06512: at line 33
Finally found the cause of the error, environment variable ORA_NLS10 not set even though successfully completed the $ORACLE_HOME/nls/data/old/cr9idata.pl executed to create $ORACLE_HOME/nls/data/9idata from upgrade notes
Retest the issue by running adstats.sql again .
adstats.sql should run successfully now.