SwiftData & CoreData Persistence

Overview

SwiftData and CoreData are NOT interchangeable. Each has specific strengths, migration traps, and performance patterns. Wrong framework choice or migration strategy causes production crashes.

Core principle: Choose framework based on app constraints, version models from day one, never store BLOBs in the database.

Framework Selection

digraph framework_choice {
    "New iOS app?" [shape=diamond];
    "iOS 17+ only?" [shape=diamond];
    "Simple data model?" [shape=diamond];
    "iCloud sync?" [shape=diamond];
    "Existing CoreData?" [shape=diamond];
    "Use SwiftData" [shape=box, style=filled, fillcolor=lightgreen];
    "Use CoreData" [shape=box, style=filled, fillcolor=lightblue];