Database Indexes

Lets understand index by a simple example.

Imagine you have a big collection of cars , and you want to find a specific car , let’s say a Red Ferrari from this collection.

Photo by Ivana Cajina on Unsplash

You could go through each car , one by one, until you find your Ferrari . This might take a while, especially if you have a lot of cars !

Now, think about if you had a special list that tells you exactly where to find each type of car . For example,

“The Ferrari cars are in lane 3.”

That list would be like an index.

In a database, an index is like that special list for finding things quickly. It’s a way to organize information so that the computer can find what you’re looking for much faster.

Here’s how it works

When you search your data without index it will go through all the rows 1 by 1 to retrieve your result.

Query :

SELECT * FROM cars WHERE name = 'Ferrari ';

Internal processing on table

But with Index when you make a query in a database (like asking for specific information), the…