Chapter 5: Working with Indexes

Indexing is one of the most important techniques used in query tuning and optimization. By using the right indexes, SQL Server can speed up your queries and drastically improve the performance of your applications. In this chapter, we will introduce indexes and show you how SQL Server uses them, how you can provide better indexes, and how you can verify that your execution plans are using these indexes correctly. There are several kinds of indexes in SQL Server. This chapter focuses on clustered and nonclustered indexes and discusses several topics, including covering indexes, filtered indexes, how to choose a clustered index key, and index fragmentation. Chapter 11, An Introduction to Data Warehouses, covers columnstore indexes in detail. Memory-optimized nonclustered indexes and hash indexes are covered in Chapter 7, In-Memory OLTP. Other types of indexes, such as XML, spatial, and full-text indexes, are outside the scope of this book.

This chapter...