Currently, sync consistency is a big priority for PowerSync. In short:

1. The local view of the data is only updated when the client has downloaded a fully consistent checkpoint.

2. It is only updated when all pending changes from the client have been uploaded, acknowledged by the server and synced back (via write checkpoints).

Details here:

https://docs.powersync.com/architecture/consistency

This does however sacrifice performance in some cases:

1. When syncing a lot of data (say a million rows), it can take minutes to sync, and in that period no data is available on the client. There are workarounds using client parameters to initially sync a smaller subset before switching to the entire set of data, but that doesn’t cover cases such as re-syncing data after sync rule updates.

2. If changes are continuously made on the client, the client don’t get any updates until that is done. A good example is our Yjs demo, where you only see another user’s updates once you stop typing.

This feature introduces the concept of a sync priority per bucket

At the moment, usePowerSyncWatchedQuery re-runs even if a different row (not covered by the query) in the watched table changes. Could cause unneeded re-renders which might become an issue in larger use cases.

This feature would only provide a diff of changes up to JS

A new type of bucket that is requested on-demand by clients with LRU garbage collection of unused buckets

This feature will enable developers to configure a custom domain in the PowerSync Dashboard which will then be used when generating your Instance URLs