Thanks for the suggestions but unfortunately it's not that simple! (is it ever?!) The duplicates I'm loading may duplicate with rows loaded yesterday or some other point in time - there are not necessarily duplicates in what i'm loading 'now' - but with what's already there.

These tables can grow to become signifcantly sized (25-30m rows, 12 columns of data) so I don't like the idea of doing a 'select *' on it anywhere!! (Our hardware isn't the best either!)

Thanks though...