Is it possible you're running out of RAM? Is there another machine you could try with more RAM?
Couple of tips:
1. Make sure you are not producing a cross-product with your join and don't generate a huge result set. Take a look at logs - are you just not getting response from Marketo?
2. Hide unused columns to minimize amount of data that's getting queried and moved around.
3. Try stripping all the calculations (if you have them) and try again. If it still fails - start removing tables from the join one by one. From what I've seen it's typically problem of #1
What's your definition or 'large' by the way?