This is the link to the book: http://bit.ly/15DSxgi
This book covers a variety of different replication solutions. It also very briefly covers some concepts not directly related to replication, but nice to know, such as CAP theorem, speed of light problem, or Linux HA. However, given the limited size of the book, all topics are discussed fairly briefly. In case of Linux HA, it actually made the explanation less than clear. I personally would exclude Linux HA from the book to save some space for more replication topics. The book gives short introductions into a few replication solutions, enough to understand how to set up a minimal replication configuration. However, this book may only be a starting point in your study of the Postgresql replication. It won’t make you proficient enough to support each replication solution in production. It would be nice to see more information on some less known tricks, troubleshooting, and monitoring. Unfortunately, the authors left out Buccardo, probably the third most popular trigger based replication solutions, but they sure have the first two most popular – Slony and Londiste. It was curious to read about Postgres-XC; though, it is not very practical, because the product is not quite mature yet to be widely used in production.
In conclusion, this is a great book for a novice Postgresql administrator who wants to get an idea about wide range of different replication solutions. It also may be nice for an experienced user who is not familiar with a particular replication solution and would like to get a general idea about it.
Overall, it was a nice reading, simple language, mostly very clear.