Welcome to Understanding Indexes, an interactive course where you'll learn how to use indexes in databases.

This course explains indexes from scratch, but it assumes that you can already create tables in SQL and select information from them. You should also be familiar with common data types, such as INTEGER, VARCHAR, and DATE. If that's not the case, we recommend first completing one of the other SQL courses we offer.

This course is divided into five parts. In the first part, we'll explain how indexes work internally. You may find the explanations here very theoretical, but they'll help you create better indexes later on. From Part 2 onward, we'll focus on the more practical aspects of indexes and we'll dive straight into the SQL code.

Are you ready?