Coskan Gundogar and Karl Arao have written two interesting articles about Oracle performance analysis and visualization, check these out!
Note that in March I will be releasing PerfSheet v3.0, which will have lots of improvements! ;-)
NB! If you want to move to the "New World" - and benefit from the awesomeness of Hadoop, without having to re-engineer your existing applications - check out Gluent, my new startup that will make history! ;-)