In this chapter we've looked at faceting—a mechanism that allows us to calculate aggregated data for our query results—and we saw the possibilities that give us the "more like this" functionality. Finally, we've discussed the percolator functionality, which allows us to use prospective search. In the next chapter, we'll learn how to control shards and replicas, how to use ElasticSearch gateway module, and what discovery is and how to configure it. In addition to that, we'll look at cluster monitoring possibilities and tools available, and finally, we'll learn how to install plugins.