Eric -

File size (actually, Aggregate size) is in the Contents table - which
is the worst of all TSM database tables to have to trawl.  If you
must, do so with as fully qualified search as possible, to minimize
sequential traversals.  An alternative would be to inspect tapes
recently used by the suspect client, using the Query CONtent command,
which is optimized for fast info retrieval.  From the TSM accounting
records, you may be able to discern such clients by the number of
backup objects being comparatively few relative to the amount of
backup data.

   Richard Sims