Partial Sync on Realm Cloud


Is it possible to do Partial Sync on Realm Cloud? Based on the previous issue I had Cloud Websocket error and based on this open ticket I’m assuming it isn’t currently available?

I’m asking because I created a realm in android (using the 4.3.3 version of the library), opened the same realm in Realm Studio and added some records. When I tried to open the realm with .partialSync() as part of the configuration it wouldn’t show those records but if I delete the app from the android device and start it up again without .partialSync() in the configuration it shows those records. No changes were made to the query, just the removal of .partialSync().

According to the tutorial on adding partial sync, the regular way to get data should work.

The last piece of this puzzle I’m hoping to figure out is the method Realm.subscribeToObjects() and how that might fit into the world of Partial Sync. Based on the Partial Sync documentation, it seems like that’s how to get objects? I didn’t try to use it but not sure what is correct, the tutorial or the docs or if it is a more nuanced reality.


When we launched the partial sync preview, subscribeToObjects was needed to explicitly specify which objects you wish to synchronize. We’re improving that with Realm Java 5.x and you’ll no longer need it but rather, we’ll create subscriptions based on the queries you use in the app. So if you’re using version 4.x, you’ll need to use subscribeToObjects to specify which queries will be synchronized with your partial Realm.


OK that makes sense, thanks for the explanation @nirinchev

Obvious question is what is the timeline for 5.0 release and Realm Cloud to support that? :slight_smile:


We’ve just upgraded ROS to a version that is compatible with Realm Java 5.x, but we’re seeing a few sporadic test failures. Once we get them to pass, we’ll deploy to our staging environment for internal testing and once we’re happy with what we’re seeing, we’ll roll it out to the public instances. At the moment, I can’t give you a precise estimate, but it’s very likely to happen next week.


@nirinchev with the announcement yesterday that the Cloud instances would be down for an update yesterday, does that indicate that the 5.0 version of Partial Sync is possible now with Realm Cloud?

Partial Sync / Reference Realm Status

Yes, it’s now available, but we have deployed only on test instances. If you’d like to live dangerously and want to give it a try, I’d be happy to deploy it to your instance.


I’m not live with the app yet so I’m happy to have it on production :slight_smile: Thanks!