Question

If I know a value being stored in MySQL is always going to be exactly 32 characters, is it better performance to make the column type CHAR instead of VARCHAR? What exactly is the performance difference between using VARCHAR and CHAR?

Thanks.

Answer 1

I would use CHAR.

If you are likely to search on the column, CHAR presents a small performance upgrade over VARCHAR.

Since your data size is going to be fixed, there is no downside to using CHAR, as an VARCHAR equivalent will store anywhere from one to two bytes as a prefix.

Reference: MySQL CHAR vs VARCHAR