Few years ago I'd understand immediately that this is about Data Access Object. But when I saw this title now, my first thought was that it is about the DAO hack [1].
While not reading it right now (read it 4-5 yrs ago) I recommend The Alchemist by Paulo Coelho. One of the few non-technical books that I really enjoyed :)
As I'm just 50 pages in, so far it's basically all familiar stuff, because I already have read most of the article series on fsharpforfunandprofit.com.
I was searching for recommendations online and people on reddit were recommending this book, together with Expert F#.
Brings back the memories from high school time, when I was helping my father in his accounting office. I was able to recognize the document being printed just by the sound pattern the printer was making :)
I never understood the hype around MongoDB. Maybe it is the fact that I started programming when SQL DBs were the prevalent/mainstream option, and got too much used to it... Anyways, Im glad people are recognizing the hype and realizing that RDBMS has enough to offer.