NSFetchedResultsController Creating Sections

When using the NSFetchedResultsController to create section headers for the UITableViewController the fetchedResultsController.sections has an object for each item not each section.

//Set up the request
NSManagedObjectContext *context = self.managedObjectContext;
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

[fetchRequest setEntity:[NSEntityDescription entityForName:@"Person" 
                                    inManagedObjectContext:context]];

[fetchRequest setFetchBatchSize:20];

NSSortDescriptor *sortDescriptor = nil;
sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"firstName" 
                                             ascending:YES];
NSArray *sortDescriptors = nil;
sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[sortDescriptor release]; sortDescriptor = nil;

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

//setup fetch results controller
NSFetchedResultsController *controller = nil;
controller = [[NSFetchedResultsController alloc] 
              initWithFetchRequest:fetchReque开发者_StackOverflowst 
              managedObjectContext:context 
                sectionNameKeyPath:@"firstName" 
                         cacheName:@"PersonCache"];

__fetchedResultsController = controller;

[fetchRequest release]; fetchRequest = nil;

//IMPORTANT: Delete cache before changing predicate
[NSFetchedResultsController deleteCacheWithName:nil]; 
NSError *error = nil;
if (![controller performFetch:&error])
{
    NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
    abort();
} else if ([[controller fetchedObjects] count] == 0){
    [self retrievePeoples];
}

NSLog(@"result count: %i", [[controller fetchedObjects] count]);
NSLog(@"section count: %i", [[controller sections] count]);
NSLog(@"sectionIndexTitles count: %i", [[controller sectionIndexTitles] count]);

This returns:

result count: 18
section count: 18
sectionIndexTitles count: 13

Shouldn't the section count and the sectionIndexTitles count match? When the numberOfSectionsInTableView: and tableView:numberOfRowsInSection: methods are called I should just be able to look to the fetchedResultsController.section for a count without any additional sorting.

How do I setup the NSFetchResultsController properly to have each object in the sections array be for per section and not for all objects?

This was answered by Phillip Mills on another forum. The problem was I was using the entire firstName to create sections (not just the first letter). The fix is to update the entity to create the a section title whenever updated or changed. Apple's DateSectionTitles has a sample of what to do.