ios - Memory increasing every core data iteration -

having memory issue while iterating through core data objects. loops through cfdata (store) keeps increasing until application crashes. shouldn't core data release memory after every loop finishes?

for (patient *patient in self.fetchedresultscontroller.fetchedobjects) {     (exam *examforpatient in patient.exams) {         //do stuff examforpatient     } } 

edit - tried following , still behaving same way:

for (patient *patient in self.fetchedresultscontroller.fetchedobjects) {     (exam *examforpatient in patient.exams) {         nslog(@"%@", [examforpatient.examdate description]);          [self.fetchedresultscontroller.managedobjectcontext refreshobject:examforpatient mergechanges:no];     }     [self.fetchedresultscontroller.managedobjectcontext refreshobject:patient mergechanges:no]; } 

when no longer have need item reside in memory, can refresh it.
docs:
"if iterate on lot of objects, may need use local autorelease pool blocks ensure temporary objects deallocated possible"

edit: see @lnafziger answer

note: if updating patient object or exam objects, cannot refresh loose changes (if use mergechanges:yes not release memory). need save periodically , refresh objects no longer need.

see here more information.