Database Search Optimization

[MrFish]

If I have a code that regularly searches a database with tens of thousands of entries (lets say it's a users database) would it be quicker to search by INT or VARCHAR or does it matter?

SELECT * FROM users WHERE id=6468

or

SELECT * FROM users WHERE username='testuser'

I would imagine that the first would be much quicker.

[justsomeguy]

An int is generally quicker to search on, but both will be fast if they are both indexed. It will be fastest if you search on the primary key.