NSFetchRequest *oldFetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *oldEntryEntity = [NSEntityDescription entityForName:@"Entry"
                                                      inManagedObjectContext:oldContext];
    [oldFetchRequest setEntity:oldEntryEntity];
    [oldFetchRequest setFetchBatchSize:10];
    [oldFetchRequest setIncludesPropertyValues:NO];
    NSArray *entrys = [oldContext executeFetchRequest:oldFetchRequest error:&error];

    int totalEntries = [oldContext countForFetchRequest:oldFetchRequest error:nil];

    int i = 0;

    while (i < totalEntries) {
        @autoreleasepool {

            Entry *entry = [entrys objectAtIndex:i];

            NSLog(@"message 1: %@", [entry valueForKey:@"message"]);


            [oldContext reset];


            i++;
        }
    }

NSFetchRequest *oldFetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *oldEntryEntity =
    [NSEntityDescription entityForName:@"Entry"
                inManagedObjectContext:oldContext];
[oldFetchRequest setEntity:oldEntryEntity];
[oldFetchRequest setFetchBatchSize:10];
[oldFetchRequest setIncludesPropertyValues:NO];
NSArray *entrys = [oldContext executeFetchRequest:oldFetchRequest error:&error];
int totalEntries = [oldContext countForFetchRequest:oldFetchRequest error:nil];

NSLog(@"entrys count = %u", entrys.count);
for (NSManagedObject *entry in entrys) {
    NSLog(@"entry: %@", entry);
}

int i = 0;
while (i < totalEntries) {
    @autoreleasepool {
        // You get the i-th entry.  It will be a managed object.  It could be a fault
        // or it could be a fully hydrated object.  Based on your batch size, the
        // first ten (0 <= i < 10) will be complete objects.
        Entry *entry = [entrys objectAtIndex:i];

        // Log the "message" attribute.  By calling valueForKey, the object will be
        // faulted into memory if it is a fault.  Since your batch size is 10,
        // this will make sure 10 objects are faulted if one is needed.
        NSLog(@"message 1: %@", [entry valueForKey:@"message"]);

        // Resetting the entire context blows away everything in the context.
        // Calling reset is a hard call, and should not be done if you have
        // references to the objects in the context.
        [oldContext reset];

        i++;
    }
}

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

while (i < totalEntries) {
    @autoreleasepool {

        Entry *entry = [entrys objectAtIndex:i];

        NSLog(@"message 1: %@", [entry valueForKey:@"message"]);


        [oldContext refreshObject:entry mergeChanges:NO];


        i++;
    }
}