Craig Shallahamer is someone we always listen from Danişment Gazi Ünal, who has written Microstate Response-time Performance Profiling paper at January 2003 and who is one of the most knowledgeable Oracle experts in Türkiye and world I have ever seen.
I saw Mr. Shallahamer’s recent Oracle Server Consolidation presentation, so here are the free publications of OraPub you might want to study.
Extract(Read) > Transform(Test&Apply) > Load(Learn) Blog 
I was reading Craig Shallahamer article for long time. But really understood whole picture , when attended one of his Seminar in New Delhi, India.