Home/ Questions/Q 6808209
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-26T19:55:38+00:00

I’m currently using NSFetchedResultController to get the to displayed data. However I’ve got two

  • 0

I’m currently using NSFetchedResultController to get the to displayed data.
However I’ve got two question about it:

1) When I set the fetchSizeBatch property to 2, my app always crashes.
What does fetchSizeBatch actually mean? I don’t really want to set it to 2, I was just playing with it and noticed that bug.

2) My app currently uses about 25 MB of memory while scrolling through the UITableView. I assume NSFetchedResultController is causing that. Is 25 MB still normal? Or is this controller some sort of device specified?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Two is an extremely low number for a Core Data batch size. According to the documentation, which probably explains it much better than I do, setting a batch size means that the data will be processed in batches; in other words, Core Data queries the database for the sorted results but only pulls the amount specified by the batch size into managed objects. The implementation of this – and this is the big part – is a proxy subclass of NSArray which will page in items from each batch whenever they’re accessed, either by index, enumeration, whatever. In your case, this means that Core Data is taking a round trip back to the database every two objects. For an NSFetchedResultsController talking to a UITableView, you can see how much of a problem this is.

    Otherwise, 25MB isn’t fantastic, but I’ve seen apps do much worse. I would say you’re good.

    • 0