What is Query Predicate

With the recent advancements and wide usage of location detection devices, very large quantities of data are collected by GPS and cellular technologies in the form of trajectories. The wide and increasing availability of such collected data has led to research advances in behavioral aspects of the monitored subjects (e.g., wild animals, people, and vehicles). Using trajectory data harvested by mobile devices, trajectories can be explored using motion pattern queries based on specific events of interest. While most research works on trajectory-based queries has focused on traditional range, nearest-neighbor, and similarity and join queries, there has been an increasing need to query trajectories using complex, yet more intuitive, motion patterns. In this chapter, we describe in detail complex motion pattern queries, which allow users to focus on trajectories that follow a specific sequence of spatio-temporal events. We demonstrate how these motion pattern queries can greatly help users to get insights from very large trajectory datasets.