Struggling with NSFetchedResultsController Performance in Large Core Data Sets on iOS
I'm prototyping a solution and I've searched everywhere and can't find a clear answer... I'm currently working on an iOS app that uses Core Data to manage a large dataset (approximately 150,000 records). I've implemented an `NSFetchedResultsController` to display the data in a `UITableView`, but I've noticed significant lag and performance issues when scrolling through the table view, especially during the initial load. I have the following setup for the fetched results controller: ```objective-c NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:@"MyEntity"]; fetchRequest.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES]]; self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil]; ``` I've also set the `delegate` for the `NSFetchedResultsController` to self and implemented the necessary delegate methods to handle updates. However, when I run the app, the initial fetch takes several seconds, and scrolling through the table view is choppy. I tried using `fetchBatchSize` to reduce the amount of data being loaded at once: ```objective-c fetchRequest.fetchBatchSize = 20; ``` Yet, this did not seem to alleviate the performance issue. Additionally, I have ensured that the main context is not blocked and I'm not performing heavy operations on the main thread. I also profiled the app using Instruments, and it appears that the `NSFetchedResultsController` is taking a long time to process the data. I've read that using predicates can improve fetch performance, but Iām unsure how to implement them effectively in my case. Any advice on how to optimize the performance of the `NSFetchedResultsController` or improve the scrolling experience in the table view would be hugely appreciated. Also, I'm developing this on iOS 15 and using Core Data with SQLite as the persistent store. Thanks in advance for your help! I'm working on a CLI tool that needs to handle this. I'm developing on Linux with Objective-C. Any examples would be super helpful.