Nice explanation of TKProf. This is related, as I need the raw trace files to use with TKProf...

I have no problem starting the first trace session using: DBMS_SYSTEM.SET_SQL_TRACE_IN_SESSION(SID, Serial#, TRUE);

When I stop the trace that is fine as well.

The problem is if I delete the trace files, then try to re-start the trace, nothing happens. I have to kill the connection, and then re-start the trace. Does anyone know why? This is on Unix. I would expect Oracle to find the files not there and then re-create them.