How does useTracker observe a collection

help
1

Hi, I’m trying to understand how does useTracker observe a certain collection and update in a real time
Lets say i sub to a publish method that returns a cursor of a collection called Messages

With every new message that is added to the collection i can see it on client because im subbed to that cursor

how does useTracker combined with sub/publish work?

and this brings me to the real question i have, If i sub to only 10 data, and i send over the wire to the client only these 10 datas,

I will never be able to know what is the size of the collection, since im limited to 10, and if i create two subs, that means i sub to all data, and then sub to 10, then whats the point? i already sent all the data and i can simply use find on client

however i want only 10 to be sent over the wire and i want to have the client listening to the collection whenever its updated to bring the whole size and be updated in real time as well

is such thing possible?

2

You can subscribe to counts as you subscribe to data. Just try to understand the size of data you subscribe to, to make sure things don’t go south after a year or two.
Initially, counting 1000 records might be lightning fast but as you go, 1 mil records may be dead slow if the count criteria is complex.