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! I am running one more Advanced Oracle Troubleshooting training in 2018! You can attend the live online training and can download personal video recordings too. The Part 1 starts on 29th January 2018 - sign up here!