Which store types does Core Data support?

Junior PRO

Essence

The store type is set when a store is attached to the coordinator (NSPersistentStoreDescription.type). On iOS three built-in types are available:

• SQLite (NSSQLiteStoreType) — the default and almost always the choice. Data lives in a .sqlite file (plus -wal and -shm with WAL journaling). It's the only type that supports lazy loading, fetchBatchSize, indexes and batch requests: a fetch runs as SQL and only what's needed is brought into memory.
• Binary (NSBinaryStoreType) — the whole graph is serialised into one binary file and loaded into memory entirely. Atomic writes but no partial loading; fine for small data sets.
• In-Memory (NSInMemoryStoreType) — nothing is written to disk. For unit tests, SwiftUI previews and temporary caches.

XML (NSXMLStoreType) exists only on macOS — a human-readable format for debugging; it's not available on iOS.

Beyond the built-ins you can write your own store — an NSIncrementalStore subclass (e.g. over a REST API or another database).