dear all
why does the direct source to DTP say "for small amounts of data"?

is this something prior to HANA, meaning, is it ok if there are large amounts of data if BW is on HANA, because i would like to run records in via ODP, this way.
also, what is "small amounts", i have 4 million records using PSA takes 20 mins, using ODP direct, that 2mins
so what constitutes to "small amounts"?
thanks