Iphone core data updating
Sometimes bugfixes add more bugs, and sometimes new features aren't improvements at all.
For one thing, if automatic updates are enabled and not just limited to Wi-Fi, then you could end up inadvertently spending huge amounts of money as every small update is downloaded over your 3G connection.
Read the Core Data Model Versioning and Data Migration Programming Guide.
When you say you don't have to consider nothing, are you saying that if the Core Data Model doesn't change, but the user does update the App, all the information stored in Core Data will still be available? The only time you really need to consider anything is if you have changed the data model.
If this remains unchanged and it is only your app coding that has changed the data will continue to be available as it was.
This chapter describes how to set up a project to use Core Data and illustrates how to implement several common use cases with the sample app.
It temporarily removes some downloadable parts of installed apps.