Realm Sync automatically synchronizes data between client applications and a MongoDB Realm backend application. When a client device is online, Sync asynchronously synchronizes data in a background thread between the device and your backend Realm app.
When you use Sync in your client application, your implementation must match the Sync Mode you select in your backend Realm app configuration. The Sync Mode options are:
- Partition-Based Sync
- Flexible Sync
You can only use one Sync Mode for your application. The Kotlin SDK only supports Partition-Based Sync.
When you select Partition-Based Sync for your backend Realm app configuration, your client implementation must include a partition value. This is the value of the partition key field you select when you configure Partition-Based Sync.
The partition value determines which data the client application can access.
You must provide a partition value when you open a synced realm.