Indexes are a feature that’s worth knowing about in SQL. They are useful for making your queries perform better, and as you gain more experience in SQL, you’ll need to know how to create them and why they are needed.
What Is an Index?
An index is an object in the database that improves the performance, or reduces the run time, of your SQL query. I like to think of it like an index in the back of a textbook.
Have you ever tried to look at a textbook for a specific topic? For example, you’re looking at a textbook on the history of human civilization and want to know more about ...
