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Editorial Team
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Asked: 2026-05-29T08:38:57+00:00

I’m battling to understand the problem I’m having with Core Data and a simple

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I’m battling to understand the problem I’m having with Core Data and a simple fetch request:

I need to display some records and I execute these lines of code

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; 
[fetchRequest setEntity:[NSEntityDescription entityForName:@"Venue"                                     
inManagedObjectContext:self.managedObjectContext]];

 NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"id_" ascending:YES]; 

NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];  
[sortDescriptor release];
sortDescriptor = nil;

[fetchRequest setSortDescriptors:sortDescriptors]; 
[sortDescriptors release];
sortDescriptors = nil;

[self.managedObjectContext executeFetchRequest:fetchRequest error:nil];

So far so good, but in Instruments I can see that before loading the records, my memory is 9mb, afterwards the memory jumps to 44mb (!!) and still there. But I want to release all the records from memory because I don’t need them anymore. Did I miss something? I thought that Core Data was releasing the records after they aren’t needed anymore. I tried to do a for-cycle to release every ManagedObject, but they are already +1 count, meaning they are soon to be released.

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1 Answer

  1. Editorial Team

    If you no longer need your NSManagedObjects, you can manually turn them back into a fault. i.e. Remove them from the NSManagedObjectContext. Next time you want them, they will be loaded from the persistent store again.

    I do this to conserve memory when I’m synchronising with a server and updating objects, but I don’t need to use them immediately.

    To re-fault, use this (and read the API Docs about it’s usage)

    - (void)refreshObject:(NSManagedObject *)object mergeChanges:(BOOL)flag
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