Oracle Hang Analysis

sqlplus -prelim /nolog 

 oradebug setmypid
 oradebug unlimit
 oradebug hanganalyze 3
 oradebug dump ashdumpseconds 30
 oradebug systemstate 266
 oradebug tracefile_name

oradebug hanganalyze 12 
oradebug dump systemstate 10 
oradebug tracefile_name