Apple stated 'the CloudKit framework should not be used to replace model objects in your app and should not be used for storing objects locally.'
My question is what should be used for storing objects locally?
Obviously I can't use a plain file, it will be slow when records getting more.
SQLite also was reported as slow in the web.
OK, for this I would advise to save each image on a file (name made of "someString" + sequentialNumber, use Archiver for stroing data in a single file, including the sequentialNumber to link with the image file.
Never experienced perf issue (even on an old iPhone 5C)
I tried this separate image file approach, it is a lot faster. User can't even feel the time for saving.
instead of using sequential number, I used the timestamp, which is easier.
