iPad/iPhone App Dev - Should I store user's data on both device's disk and database?

Question

I am new to iPad/iPhone apps/games development.

I am developing a game. The game will need to user's inventory like the current wear, what items have s/he bought. I have read through the core data and sqlite3 for iPad/iPhone. Here is my questions:

1. Is core data(using sqlite3) can only store data on the phone only?

2. Do I need to store in a web database(probably like: obj c -> php -> database -> obj c)

The reason I asked the second question is, I downloaded and installed some iPad games, I play it until certain level, purchase some items. Then, I uninstall/remove the game from my iPad, and the I re-install the game again. When I play again the game, the game recognize my identity, it recognize what level I was, what items I bough. And this make me though that, it could be store somewhere on the developer's database. Am I wrong?

1. Whats the best practices? Store data on phone (using core data), store on online database (mysql through php) or store on both location? Please advise.

Thanks.

Answer 1

There is a procedure to restore purchases on the appStore.

http://developer.apple.com/library/ios/#documentation/NetworkingInternet/Conceptual/StoreKitGuide/MakingaPurchase/MakingaPurchase.html