tkprof question

I want to see the "wait events" along with my cost for a particular query.

My environment:

Sun Solaris (SUNOS 5.9)
Oracle 9.2.0.7

TIMED_STATISTICS is not set in the parameter file....

So, I am doing

SQL> alter session set sql_trace=true;
SQL> alter session set timed_statistics=true;
SQL> "running the SQL here"

After getting the trace:

$ tkprof <trace file> <output file> explain=... sys=no waits=yes

But the "output file" never produces the "wait events"

Any ideas?

TIA Nirmalya

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