How to generate trace from Different Session ?

  Detailed Steps to enable trace from different session
 ------------------------------------------------------
 1. In SQL*Plus: connect with a DBA account and query all the sessions:
 .
 SQL> select username, sid, serial#  from v$session where
 username=<User_name>;
 .
 USERNAME                             SID   SERIAL#
 --------------------------------------------------------
 OWB_DESIGN_REP                  14      13202 
 OWB_DESIGN_REP                  15       4665   
 .
 2. In SQL*Plus: When you know the SID and the SERIAL#, you can enable the
 trace for EACH session running command: 
 .
 EXECUTE DBMS_SYSTEM.SET_SQL_TRACE_IN_SESSION(<SID>, <SERIAL#>, TRUE)
 .
 So in this example you would need to do following:
 .
 SQL> EXECUTE DBMS_SYSTEM.SET_SQL_TRACE_IN_SESSION(14, 13202, TRUE)
 SQL> EXECUTE DBMS_SYSTEM.SET_SQL_TRACE_IN_SESSION(15,  4665, TRUE)