The obvious strategy is to install more RAM.
If you start with the claim, that the function you want to use requires the complete data set to be loaded at once, there is no way to escape from the need to load the complete data set at once. If this is not possible for your computer, upgrade it or run the code on a more powerful computer.
Sorry, I know that this answer is trivial. But it is the only possible answer matching your question exactly. Of course you could apply a data compression in the RAM or condense the data at first. But this is not exactly what you are asking for, and in addition, it would be much more expensive most likely.
