Day 9. Indexes and Performance
So far, you have learned how to use T-SQL to access and manipulate data in your SQL Server database. In Day 8, "Defining Data," you were introduced to the Data Definition Language, or DDL, which is used for creating and modifying the definitions and structures of the tables used in a database. What we haven't looked at yet, is how to make your database perform better. There are many database programmers who have spent years working with SQL without any real understanding of how the SQL Server works or what decisions it makes for them.
However, in these days of ever growing databases, you are required to write faster, more efficient application systems. To do this, you need to know more about how the server processes queries. Today, we are going to develop an understanding of the different types of indexes available to you in SQL Server, and then see how the server uses them to optimize query performance. Some of the topics that are going to be covered are