[galaxy-user] Join and Sort in Galaxy

Hello, I have some questions about the Join and Sort tools in Galaxy. How are they implemented? Just the standard unix sort and join? I have a quite large tab file (~1,5 million lines), I want to join with a somewhat smaller file (~20 000 lines). How long will this approximately take? Is there a way to view the progress? Can I gain performance if do a sort on the column I want to join? thx, Felix