magicalpanda / MagicalRecord

Super Awesome Easy Fetching for Core Data!
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Prefetching isn't working (Apple Bug) #1099

Open nadavhart opened 8 years ago

nadavhart commented 8 years ago

Hey,

It seems prefetching isn't working when executing a NSFetchRequest using a NSManagedObjectContext which has another context as its parent. When context has a store coordinator as a parent prefetching works fine. Note that this is reproducible on iOS 8 & iOS 9.

This isn't a MagicalRecord issue, but as MR uses a family of happy contexts to be the awesome component that it is, I thought that it should be brought to your attention & documented here until Apple fixes it.

Link to a small project which reproduces this issue - https://dl.dropboxusercontent.com/u/24851476/TestPrefetch/TestPrefetch.zip

Links to logs (with com.apple.CoreData.SQLDebug set to 2): https://dl.dropboxusercontent.com/u/24851476/TestPrefetch/ConsoleLogWithoutParentContext%20%28Prefetch%20working%29.rtf https://dl.dropboxusercontent.com/u/24851476/TestPrefetch/ConsoleLogWithParentContext%20%28Prefetch%20not%20working%29.rtf