I noticed that the docs mention that the newly introduced shared CloudKit databases do not support CKQuerySubscription (in earlier iOS versions these were called CKSubscription). So I guess that means that it is not possible to notify users when privately shared records have changed. Major disappointment. Has anyone run into this problem?
According to the WWDC video about CloudKit this year:
So, new this year in iOS 10, there's an API called CKDatabaseSubscription.
This allows you to subscribe to any change across an entire database, and it works in a private database, in a shared database.
It shows you how starting on slide 51:
来源：https://stackoverflow.com/questions/38945807/ckquerysubscriptions-are-not-supported-in-a-sharedclouddatabase