MYSQL VARCHAR or CHAR for fixed length string
char, mysql, varchar
Solution
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
Problem
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.