Mysql TINYINT和VARCHAR性能

Question

I have a column build in mysql db, it store the value - 10000 in TINYINT , what if I change it to 10k VARCHAR which one will be better performance?

ex. 10000, 20000, 30000.... or 10k, 20k, 30k...

Answer 1

If you are just selecting the value then it doesn't matter.

But if you are using it in a where condition then the performance will be better using an int . Example:

select * from your_table
where your_column > 1000

will only work if the column is an int and you don't need to convert it back to a number.

Generally - if it is a number - store it as number.

Answer 2

The bigger question is -- would it help your project? With TINYINT you can perform math operations on it. You can't do that with VARCHAR , since your numbers would be a string. Sure you could manipulate the string into a number, but that'll cost you in performance as well as the need to make extra code (which can unnecessarily complicate the SQL or other language).

If you're going to make a value be a number -- then by all means make it an integer . There's a reason really really smart people made a difference between string's & int's.