Question

I don’t understand the meaning of setFetchBatchSize.

In the following code, I set the fetch batch size to 20, but I still get 49 objects in my results array (which are ALL the objects from the query)

        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"company.id = %@", company.id];
        NSFetchRequest *req = [CategoryEntity requestAllSortedBy:@"id" ascending:YES withPredicate:predicate];
        [req setFetchBatchSize:20];
        NSArray *results = [CategoryEntity executeFetchRequest:req];

So what’s the meaning of setFetchBatchSize, since it doesn’t seem to limit the request?

Answer 1

To limit the size use fetchLimit.

With batch size, the objects are faulted. They look like they are there but those are just stubs. When you access them – behind the scenes – the values are then populated.