I first read this book about 6 years ago to get a deeper dive into the internals of SQL Server 2012. I definitely learned a lot. But I think I picked up, even more, the second time through. Considering I have actually met all the authors from SQL Saturday events or the annual PASS Summit. But, I think having taught SQL performance tuning over the last 6 years that I was able to really understand the concepts at a more detailed level. Now, this version of the book is for SQL Server 2012 and there have been at least three versions of SQL Server released since then with 2019 coming very soon. But the majority of this book is still relevant for all of those versions. An updated version would be welcome with some of the newer features added, but this is definitely a book I will most likely be reading again.