maximum length of Digital Object Identifier?

Question

I want to add a field to my database that stores DOIs. But I can't seem to find out what their maximum length is. Does anyone know if there is a maximum length?

Answer 1

never mind, I found it:

http://www.doi.org/doi_handbook/1_Introduction.html#1.6.3

DOI names have two components, known as the prefix and the suffix. These are separated by a forward slash. The two components together form the DOI name:

10.1000/123456

In this example, the prefix is "10.1000" and the suffix is "123456".

There is no technical limitation on the length of either the prefix or the suffix; in theory, at least, there is an infinite number of DOI names available.

Answer 2

From a 10K sample, I would go for 255 as max length to be on the safe side...