How to trace a session in MTS (8iR3)

Hello, fellows!
First of all, congratulations for the high sound to noise ration in this list. I've no doubt it's the best one I've ever participated.

My doubt:
I've been working for the last four years with 8i and 9i, always configured to dedicated connections. Nowadays, in my new job, I'm playing for the 1st time with MTS in 8iR3.

We have a very big HPUX box (12 CPUs) and during the whole day the top CPU processes are in the format 'ora_sNNN_dbname'. I noticed that these processes have different multiple sid/serial# in different times. How do I trace what these processes are doing to consume a lot of CPU? What do you use to do when facing a scenario like that?

Taking a session-to-processes look, I noticed that the same session (SID) has different SPID in v$processes during its lifecycle. So, when people call me saying that a reporting is longing more than 10 times the usual time, how do I trace that specific session in MTS?

Have you a nice day!

Thanks in advance,
Luis
from Brazil

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