Summary

In this chapter, we covered a basic understanding of indexes, how to create, drop, alter, or modify an index, and how to rename an index. Then we learned about index types based on the storage, a basic understanding of clustered, non-clustered, covering, unique, and filtered indexes, and how to create these with examples. Then we learned about the impact of indexes on query design and the impact of indexes on query performance.

We learned about how an index improves performance, along with how it can degrade the system’s performance. We learned we should always be cautious before creating indexes in production.

In the next chapter, we will expand our knowledge of and understand the basics of the JSON file format and how SQL Server handles JSON data.