This isn't really a bad book, but given the clarity with which PostgreSQL's official (and free) documentation is written, a lot of it also isn't necessary. Sure, it's really thick, but a lot of those pages are dedicated to really ugly screenshots and Windows-specific silliness I'm willing to bet few members of this product's target audience are particularly interested in. There are also entire chapters dedicated to C# and Java APIs which should probably be separate books if they really wanted to do justice to such topics--their inclusion here just feels like pointless filler.
If you have absolutely no idea what SQL is and want to get your feet wet with Postgres, then this is absolutely the book for you. If you have a pretty good idea what you're doing and just want to pick up on some of Postgres' quirks, I'm not too sure you'll be getting your money's worth here. It just tries to cover way too much ground too quickly, and the information ends up getting stretched a little thin.
