I have a database in CloudKit, where the host share (using CKShare) a record to participants. The record is in her private database, but for the participants is in their shared database. How do I send push notifications to everyone when a new child record is created?
Where you are using CKRecordZoneSubscription to sync the private database, you can use CKDatabaseSubscription to sync shared databases.
See CloudCore for an example.
Are you syncing CloudKit to CoreData? I create an observer singleton with a FetchedResultsController, detecting when changes occur in the root object (as synced from CloudKit), and post local notifications as appropriate.
See CarShuffle for an example