For starters: The PostgreSQL 9 High Performance book is a more advanced book than the PostgreSQL 9 Admin Cookbook and is more of a sit-down book. At about 450 pages, it's a bit longer than the PostgreSQL Admin Cookbook. Unlike the PostgreSQL 9 Admin Cookbook, it is more a concepts book and much less of a cookbook.
It's not a book you would pick up if you are new to databases and trying to feel your way thru PostgreSQL, however if you feel comfortable with databases in general, not specific
to PostgreSQL and are trying to eek out the most performance you can it's a handy book. What surprised me most about this book was how much of it is not specific to PostgreSQL, but in fact hardware considerations that are pertinent to most relational databases.
In fact Greg Smith, starts the book off with a fairly
shocking statement in the section entitled PostgreSQL or another database?There are certainly situations where other database solutions will perform better. Those are words you will rarely hear from die-hard PostgreSQL users, bent on defending their database
of choice against all criticism and framing PostgreSQL as the tool that will solve famine, bring world peace, and cure cancer if only everyone would stop using that other thing and use PostgreSQL instead:).
That in my mind, made this book more of a trustworthy reference if you came from some other DBMS, and wanted to know if PostgreSQL could meet your needs comparably or better than what you were using before.
In a nutshell, if I were to contrast and compare the PostgreSQL 9 Admin Cookbook vs. PostgreSQL High Performance, I would say the Cookbook is a much lighter read focused on getting familiar with and getting the most out of the software (PostgreSQL), and PostgreSQL High Perofrmance is focused
on getting the most out of your hardware and pushing your hardware to its limits to work with PostgreSQL. There is very little overlap of content between the two and as you take on more sophisticated projects, you'll definitely want both books on your shelf. The PostgreSQL 9 High Perofrmance book isn't going to teach you
too much about writing better queries,day to day management, or how to load data etc, but it will tell you how to determine when your database is under stress or your hardware is about to kick the bucket and what is causing that stress. It's definitely a book you want to have if you plan to run large PostgreSQL databases or a high traffic
site with PostgreSQL.
PostgreSQL 9 High Performance is roughly about 25% hardware and how to choose the best hardware for your budget, 40% in-depth details about how PostgreSQL works with your hardware and trade-offs made by PostgreSQL developers to get a healthy balance of performance vs. reliability, and another 35% about various useful monitoring
tools for PostgreSQL performance and general hardware performance. Its focus is mostly on Linux/Unix, which is not surprising since most production PostgreSQL installs are on Linux/Unix. That said there is some coverage of windows
such as FAT32/NTFS discussion and considerations when deploying terabyte size databases on Windows and issues with shared memory on Windows.
Full disclosure: I got a free e-Book copy of this book just as I did with PostgreSQL 9 Admin Cookbook.