This policy merges conflicts between the persistent store’s version of the object and the current in-memory version, giving priority to external changes.
The merge occurs by individual property. For properties that have been changed in both the external source and in memory, the external changes trump the in-memory ones.
Available in Mac OS X v10.4 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)