The only sure way to avoid making mistakes is to have no new ideas.
In Chapter 8, a default data import from an XML file was demonstrated. This import method is suitable only when the XML source file is small enough to fit into memory. Another option is to use a pre-populated persistent store as the initial persistent store. If customers already have existing data and you want to add a lot more to it, this option isn’t suitable either. When you find yourself in this position, you may need to perform a ‘deep copy’ of managed objects from a source persistent store to an existing persistent store.
A deep copy involves copying managed objects and their relationships from one persistent store to another. Once ...