Hello,
During my checking for one of users issue found one useful SDE document,
Which i want to share to all Geonet users.
FYI, The document you posted is from 2002 and covers ArcSDE 8.1. Most, if not all, of this document no longer applies.
That is true, but it is the last one that came out as a physical book, and I keep it around too because there is useful information in that book that was never included in the online help. I was told by esri tech staff a while back that if I have a copy, hold onto it. Not all of it applies anymore, of course, but there is information that can help you understand SDE a bit better. In my opinion.
I remember this document! Good find for the history of the SDE evolution - much has changed, but still helpful to understand the architecture of SDE.