This book sets out to cover the entire Hadoop environment, it's a big book but that's a massive subject and it'd be a major challenge to cover in one book. As a result that majority of the book is on the core of Hadoop, HDFS and classic MapReduce. The sections on Pig, Hive and HBase feel tacked on and aren't in any where near as much depth as the initial section of the book. Because it's a 2012 book, it also ignores some of the newer technologies like Spark and Impala.
So it's a good introduction to Hadoop, but a long way short of being "The Definitive Guide".