Oracle Database Discussions

Hi friends,
I am studying the book Apress Troubleshooting Oracle Performance by Christian Antognini. He has provided few methods of tracing others sessions.

1st method:
dbms_system.set_ev(si => 413, -- session id
se => 8015, -- serial number
ev => 10046, -- event number
le => 12, -- level
nm => NULL)

2nd method:
dbms_monitor.session_trace_enable(session_id => 413,
serial_num => 8015,
waits => TRUE,
binds => FALSE)

I tried both these on my database at work place and both doesnt seem to work. I confirm this by running the below command and i get sql_trace column value as false.

SQL> SELECT sql_trace, sql_trace_waits, sql_trace_binds FROM v$session WHERE sid = 413;
SQL_TRACE SQL_TRACE_WAITS SQL_TRACE_BINDS
--------------- --------------- ---------------
FALSE FALSE FALSE

SQL> select *from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bi
PL/SQL Release 10.2.0.3.0 - Production
CORE 10.2.0.3.0 Production
TNS for Linux: Version 10.2.0.3.0 - Production
NLSRTL Version 10.2.0.3.0 - Production


The only way i am run the trace is tracing own session by running the below command:
alter session set sql_trace=true;


Can someone please help me with how to trace other's session in oracle 10g?

regds,
Kunwar