Junior — Middle
Have you had experience performing data or system migration processes?
sobes.tech AI
Answer from AI
Yes, data migration experience in iOS is usually related to updating the Core Data structure or transferring data between application versions. For example, when changing the data model in Core Data, migration must be implemented to preserve user data without loss. This can be a lightweight migration when changes are simple, or a custom migration with writing your own code to transform data.
Example of lightweight Core Data migration:
let container = NSPersistentContainer(name: "Model")
let description = container.persistentStoreDescriptions.first
description?.shouldMigrateStoreAutomatically = true
description?.shouldInferMappingModelAutomatically = true
container.loadPersistentStores { (storeDescription, error) in
if let error = error {
fatalError("Unresolved error \(error)")
}
}
Migration may also include transferring data from an old format (e.g., UserDefaults or files) to a new database or storage format.