What's the consequence when Core Data detects an optimistic locking failure when trying to save?

Question

I get it: When a managed object context saves, the snapshots of all edited objects are compared against the values in the persistent store to see if the PS has changed since the snapshot was made.

If it did change, then there's a conflict and optimistic locking failed, according to Apple. But now, what's the consequence of this? What happens next? What are my options in this case?

Answer 1

Take a look at the mergePolicy setting on the NSManagedObjectContext. The default is to produce an error but you can change that to something that makes sense in your application.