---
title: NSUUIDChangedPersistentStoresKey
framework: coredata
role: symbol
role_heading: Global Variable
path: coredata/nsuuidchangedpersistentstoreskey
---

# NSUUIDChangedPersistentStoresKey

Key for an array containing the old and new stores.

## Declaration

```swift
let NSUUIDChangedPersistentStoresKey: String
```

## Discussion

Discussion The object at index 0 is the old store instance, and the object at index 1 the new. When migration happens, the array contains a third object (at index 2) that is an array containing the new objectIDs for all the migrated objects.

## See Also

### Constants

- [NSAddedPersistentStoresKey](coredata/nsaddedpersistentstoreskey.md)
- [NSRemovedPersistentStoresKey](coredata/nsremovedpersistentstoreskey.md)
- [NSPersistentStoreConnectionPoolMaxSizeKey](coredata/nspersistentstoreconnectionpoolmaxsizekey.md)
- [NSPersistentStoreSaveConflictsErrorKey](coredata/nspersistentstoresaveconflictserrorkey.md)
- [NSPersistentStoreUbiquitousTransitionTypeKey](coredata/nspersistentstoreubiquitoustransitiontypekey.md)