Advanced MySQL 8

What kind of data type should I consider indexing first and why?

From a performance point of view, creating indexes is essential for system performance and future maintenance of your MySQL server database. Choosing the right indexes can give a significant boost to your application's performance.

In principle, the less space the column takes up, the faster your index will be. So, for example, what would be the column that would be the best candidate for a quick index, an INT or VARCHAR?

The answer would obviously be INT because the space used will be less than the VARCHAR. So, if performance is critical for you—and is probably why you're reading this book—I'll tell you that if you have the chance to have the smallest number possible, the better ...