Does Firebase synchronize the entire database, or in parts?

Question

Android

I have a DB ~ 30Mb. You need to update it without updating the application. I thought about using Firebase, but the question arose about traffic: let's say if I change one line, will the entire 30Mb snapshot go to the device? Or will it only send the changes?
Just if the whole snapshot - I'm afraid I won't pull it financially)))
Thank you in advance!

Answer 1

The snapshot will contain only part of the tree.