Check Oracle Blocking Locks

SELECT to_char(sysdate,'yyyy-mm-dd hh24:mi') dttm
     , ' --- BLOCKER --- '
     , lo.session_id 
     , lo.process
     , lo.os_user_name
     , dob.object_name
     , dob.object_type 
     , ' --- BLOCKING --- '
     , s.sid
     , s.username
     , s.status
     , s.schemaname
     , s.osuser
     , s.process
     , s.machine
     , s.terminal
     , s.program
     , s.sql_hash_value
     , s.logon_time
     , p.spid
     , l.id2
     , l.ctime
  FROM v$session s
     , v$process p
     , v$lock l
     , v$locked_object lo
     , dba_objects dob
 WHERE s.lockwait is not null
   AND p.addr(+) = s.paddr
   AND l.sid = s.sid
   AND l.type='TX'
   AND l.id2 = lo.xidsqn
   AND lo.object_id = dob.object_id;