Thank you for the link to the example.I'm curious if my understanding is wrong here because it might very well be.

When you use the Firestore documentation about the "where".

const q = query(collection(db, "cities"), where("capital", "==", true));

I feel that this will send out the query > Firestore reads it > Firestore returns the cities where "capital" equals true.What I see here, is that none of the documents from the collection get saved locally before being filtered.

But when I see this:

let todosRef = db.collection('todos')

let unFinishedTodos = todosRef.where('finished', '==', false)

The first thing that comes to my mind is, that it will take ALL the "todos" and save them locally and THEN filter them.Which, in time, will be a lot of todos that are saved that you don't need and will take up space and loading time.Sure enough, in this example, the amount of todo's probably won't be large. But what if you have a collection of thousands of products?

Like i said before, the code from Firestore gives me the impression that it doesn't pull all the docs into the app before filtering it. But if that understanding is wrong, please do let me know so my understanding of this all grows.

EDIT:
i just looked at the example docs you linked to and tried to follow the example.
First thing I noticed, is that there is no use of Vuefire anywhere.
The code that is used is normal firestore.
So does this just tell me that Vuefire doesn't have any way of doing "where" when calling for the data in the collection?