Let me begin by saying that credit for this find goes to @jonnyknowsbest on Twitter and his SO post here: Primary Key issue on iOS8 implementation of IndexedDb. I did my research into this issue early this morning and I hope that I, and jonny, are both wrong. I'd love to be wrong about this. Unfortunately, I don't think that is the case. So, as you know, iOS 8 finally brought IndexedDB to Mobile S