Updating an iPad App with a Completely Different Architecture

I've been updating my iPad app very steadily now and the process has been fine. But in a month or so, I'm going to be upgrading it to a version that has a completely different architecture.

Both versions will be using the cache and db开发者_C百科 in very different ways to store the data it's pulling from a server.

Question: Will the Apple update process automatically delete all local data from my previous version upon installing the new version? Or, do I have to code this functionality in somewhere in my new version?

Example: Some files you download on Windows don't remove the data from "Application Data" or "Local Settings" upon uninstalling. I fear that this same scenario will happen on my iPad when upgrading my app to a completely new version. Is this the case?

Thanks, Derek

No, the update process does not delete files that you have in the app's documents folder. They will still be there.

iPhone and iPad updates do not remove data from previous version installations of an app. Your app will have to detect (say, look for the current version number) the old databases, and either delete them, or perhaps better for the user, update them to the new format.

Make sure to somehow tag the new data format with a version number so your app can detect it, and not delete it.