I agree with Tom. Store the original: let the frontend uppercase themselves
if they want it that way. If they decide to force the transforms back down
to you, you won't have spoiled your input. If they are querying on that
column, a functional index on lower(col) would be nice. To answer your
original question, yes, let the front end deal with the problem, leaving
you time to worry about more traditional database-related problems. :)
Cheers,
Greg