Chapter 3. Searching Your Data

In the previous chapter, we ped into Elasticsearch indexing. We learned a lot when it comes to data handling. We saw how to tune Elasticsearch schema-less mechanism and we now know how to create our own mappings. We also saw the core types of Elasticsearch and we used analyzers – both the one that comes out of the box with Elasticsearch and the one we defined ourselves. We used bulk indexing and we added additional internal information to our indices. Finally, we learned what segment merging is, how we can fine tune it, and how to use routing in Elasticsearch and what it gives us. This chapter is fully dedicated to querying. By the end of this chapter, you will have learned the following topics:

• How to query Elasticsearch
• What happens internally when queries are run
• What are the basic queries in Elasticsearch
• What are the compound queries in Elasticsearch that allow us to group other queries
• How to use position aware queries – span queries
• How to choose the right query for the job