While shortname acts as an alias for a class (see OrientDB Issue 901 - "...change shortName to alias" in some contexts, it seems that shortname can't be used universally in reference to the class. For example:
select from <shortname>
works as expected, selecting the records associated with the class for which shortname is an alias;drop class <shortname>
, however, does not actually drop the corresponding class (just tried this with version 1.6.3).
Unfortunately, you'll probably have to do your own instrumentation to determine runtime performance and/or disk usage for your application.