Understanding Indexes

Working with Indexes is the final course in the Creating Database Structure track . You should already know how to create tables in SQL. If not, take The Basics of Creating Tables in SQL course first. After you complete that, we recommend doing the Data Types in SQL, SQL Constraints, and Working with Views courses. These will give you the foundation you need to complete this course.

In this course, we talk about indexes. These are internal structures that help the database process SQL queries more efficiently. There are many kinds of indexes, but we’ll focus on B-tree indexes – the most common type. You will learn how to create, modify, and remove indexes.

Even though database indexes are present in all relational database engines, the SQL standard doesn't define a specific syntax to create them. We’ll explain the syntax commonly used in the most popular relational database management systems (SQL Server, MySQL, Oracle, and PostgreSQL).

Are you a programmer, developer, or beginning database administrator (DBA) who needs to deepen your SQL knowledge or improve database performance? Start learning indexes today. Working with Indexes is also great for computer science students who want to build their relational database skills.

Topics discussed in the course include:

• Indexes. Look at the anatomy of the B-tree index and overview other types of database indexes.
• Basic syntax. Understand the basic CREATE INDEX syntax.
• Creating indexes. Learn when it’s worthwhile to create an index and how it affects SQL queries.
• Advanced topics. Discover partial indexes, clustered indexes, and indexes that use expressions and functions.

The course is interactive. You’ll learn how to create and alter indexes by writing real SQL commands. You solve the exercises directly in your web browser; our platform runs your command and verifies your solution. You don’t need to install any extra software to run this course.