Help! how to perform union, intersect, setdiff ?

I'm dealing with large datasets (more than 100000000 rows). They all have the same variables, but they are huge! 
AlI have to do is pick two of these datasets and apply basic set functions (union, intersect, setdiff). No problem with smaller datasets, just using dplyr. I approached disk.frame but I can't find a fast way to do the same. Anyone can help? Thanks