Summary

In this chapter, you practiced improving query performance. You first explored the internal workings of query execution and the query execution stages. You then learned how to analyze a query's performance and identify any existing problems based on the execution statistics. Next, you reviewed the concept of indexes; how they solve performance issues for a query; various ways to create, list, and delete indexes; different types of indexes; and their properties. In the final sections of this chapter, you studied query optimization techniques and got a brief look at the overheads associated with indexes. In the next chapter, you will learn about the concept of replication and how it is implemented in Mongo.