Yesterday I enabled the synchronization for an index-only database on my iPad. The database does not contain documents itself; it only indexes a directory under
~/Documents on my Mac, which in turn is synced with iCloud Drive. I didn’t expect DTTG to be able to open files within the database since they are not actually stored in it. Surprisingly, DTTG does open them with no issue. I also tried to make some annotations on a PDF and it was successfully synced back to the original copy in the iCloud Drive.
Of course, it‘s wonderful — but how can this be possible? Is it because both the documents and the database indexing them are stored in iCloud?