Delta fetch & modify records

For the current version, I'd say IceCream works perfect. It has been served to thousands and thousands of users so far and with 99% of users are happy with it. So thanks IceCream.

What troubles me is our users may have many photos to store in the app, so there are many CKAssets had been created.

The problem is Every Time users make a little bit change, like update a title. The whole CKRecord is updating to the iCloud and another device will receives the whole CKRecord from iCloud. If a CKRecord contains many CKAssets or the size of those CKAssets is really big. Then every single update is really time-consuming.

I know Realm cannot observes which fields are changed for an Object. And also it's harder to know which fields are changed in the iCloud, so we cannot use desiredKeys to fetch only changed fields for a CKRecord.

Just propose this issue for a better practice. If anyone knows any better way to handle these two problems, would be very appreciate.

Thanks

P.S. In short, The questions would be

• How to fetch only changed CKRecord's fields from iCloud?
• How to modify only changed CKRecord's fields to iCloud?