How smart is the firestore update protocol

Question

I am implementing an application that updates a document each second.

All connected users are listening to this document.

The document that I update is quite big (ca 40k as json) but most of the times I am only updating a single field in that document.

So I wonder if I should break this data out into its own document or if the protocol that firebase/firestore uses is smart? Ie so that it only sends out the modifified data.

Answer 1

The Firestore client sends the data that you pass to the API call. So if you call documentRef.update() with a single field, it sends just the path to the document and that field. If you call documentRef.set() or .update() with more fields, it passes the path and those fields.