I had this great post planned out only to realize I had been beaten to the punch.
Instrumenting OBIEE for tracing Oracle DB calls
Mr. Moffatt [ LinkedIn | Twitter ] describes a way to go about finding out exactly what was being run by using DBMS_APPLICATION_INFO.
If you are working with OBIEE, any version, I would encourage you to go read his article.
What's amusing to me, is that we both tried (well, I tried, he did) to do the same after reading Cary Millsap's excellent paper, Mastering Performance with Extended SQL Trace.
I heckled Mr. Moffatt a little bit privately for stealing my thunder, but after reflection, I was thankful...I didn't have to do all that work.