This has lasted a little bit longer than seven weeks (the release schedule of the beta versions did not help; my day job did not help either), but finally I finished the book.
I liked that the book started with PostgreSQL. All too often, I am put of by the amazingly uninformed criticisms of the NoSQL crowd about relational databases; this left me with the general impression that a younger generation of engineers was just too ignorant to figure SQL out, so they build something new (without the benefits of decades of experience…).
By having a balance approach, the book cleared this misconception (Hadoop, the Definitive Guide also has a balance coverage in its introduction).
Each database’s strengths and weaknesses are correctly (as far as I can tell) reported, along with its position in the CAP triangle, and intended or ideal usage.
A recapitulative (but already partially incorrect, at least in the 5.0 beta version) overview of all the databases properties in Appendix A is also very useful.
Well, this is not exactly a problem of the book itself, but rather of the tools it covers: the rapid and sometimes radical changes in some of the databases meant that the technical information in the book was already obsolete.
The book’s intention is not to be a detailed tutorial; for instance, they skip installations (really, most technical books should skip installation and go straight to setup and use; think of the number of trees that would save), but the search for corrections was heavily taxing my already sparse free time.
All this will eventually improve, as the tools and documentation mature; right now using them is a bit too involved for the broad but shallow approach this book follows.
Compared to Seven Languages in Seven Weeks, I found this book more challenging. But this is perhaps a consequence of my prior exposure to a variety of languages and programming concepts; I suspect many people may find this book much easier.
Of all the books I have read recently, this is the one that changed and enlarged my views the most.
If you are, like me, a traditional software engineer with years of experience in relational databases but little exposure to newer kind of storage, you will benefit from this presentation of many databases and solution designs.
If, however, you already come from the NoSQL database and have experience in a few of the covered tools, this one book might not be the ideal one to convince you of the strengths of PostgreSQL. The problem with relational databases is that, having been the defacto standard storage solutions for decades, nobody remember why they became popular in the first place (they actually replaced databases that looked pretty much like document or graph databases, only much more primitive).
Still, given its price, as a broad introduction to many different data tools and techniques, this book is hard to beat. I certainly am glad for having read it, and I think you would be too.