In this chapter, we learned how Elasticsearch indexing works. We learned to create our own mappings that define index structure and create indices using them. We learned what batch indexing is and how to use it, and how we can index our data efficiently. We also learned what additional information can be stored along with the documents. In addition to that, we've seen what segment merging is, how to configure it, and what throttling is. Finally, we used and configured routing.

In the next chapter, we will concentrate on searching. We will start with how to query Elasticsearch and what the basic queries we can use are. In addition to that, we will use filters and learn why they are important. We will see how we can validate our queries and how to use the highlighting functionality. Finally, we will use compound queries, we will get into querying internals, and we will sort our results.