1,000s, 10,000s, 100,000s, millions. MongoDB columns are designed for serialization of rich documents, not store unbounded ranges of data values. Even without

1,000s, 10,000s, 100,000s, millions. MongoDB columns are designed for serialization of rich documents, not store unbounded ranges of data values. Even without tens of thousands of concurrent users, you'll eventually run into a deeply critical performance wall when MongoDB starts reading from disk. It's really best to think of it as an in-memory database.