Got this persistence memory overload when importing data from a Google Docs spreadsheet into Core Data.

XXXXX <89476b67fcbc4c49f1ba498af5d06040>   17483 (jettisoned) (active)

Give up after 17483 count.  At the moment is using [managedObjectContext save:&error] at the end of the input.  Maybe can consider saving every record at the end of each loop.