in reply to Hardware to run heavy dbix::class stuff?

That while-loop will indeed be the real killer, but you should be able to replace it by some aggregating SQL query.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James