I have a table which will contain a set of pre-defined records defined by the government of my country. The fields are ID and DESCRIPTION. The ID field is composed of 3 characters that are always numbers. This means that I can set such a field as a char(3), varchar(3), smallint or integer, for example, and all of them will provide the correct functionallity. My question is, why should I define such a field as a character based type or a numeric based type? What is the best choice if this field will always be a 3-digit number?
