The theme of this book is spatiotemporal databases of moving objects. Specifically, it presents recent research results concerning the efficient processing of complex motion/trajectory pattern queries. At the heart of these queries lies the concept of the flexible pattern query, which is a type of query that allows users to select trajectories based on various types of events.

The book consists of four main chapters. The second chapter explores the notion of flexible pattern queries and how they can be formulated as regular expressions over a spatial alphabet. Moreover, the authors introduce a couple of join algorithms for evaluating spatial predicates. In the next chapter, the authors present a complete system for posing and answering spatiotemporal queries, namely the spatiotemporal pattern system, which can be used in various environments, for example, for processing mobile phone call data and in radio-frequency identification (RFID) environments. In chapter 4, the authors generalize the idea of flexible pattern queries to the case of discovering interesting aggregate events by treating trajectories in groups. Finally, effective and efficient methods for providing answers to pattern queries that are relevant to the query, and diverse to the other returned results, are discussed.

It is understood that due to the nature of the book--that is, the very limited number of pages--the authors were constrained as far as the material that they could include. Nevertheless, they could have dealt with topics related to uncertainty in mobile trajectories, privacy preservation, and result ranking.

Even though the ideas presented have been published earlier as research papers, the book itself is worth reading. It is intended for postgraduate students or senior researchers working on topics related to storing and processing mobile object trajectories. Overall, the topic of this book is significant because it touches on a current hot topic.