I'm using Core Data (with sqlite) in an iOS app and currently adding some new attributes to an entity. I'm up to around 110 attributes. I realise this is a lot, but when I tried to organise the data in a different way I found it impossible to keep my app working reliably.
Xcode is now giving me a warning: "Misconfigured Entity: Entity has more than 100 properties; consider a more shallow entity hierarchy or denormalized properties."
I don't know what it means by denormalized properties, but let's say I'm keen to keep my data model the way it is. I never normally ship code that has any warnings of any sort. But can I safely ignore this warning, at least for the time being until I work out a better way to structure my data?
You should move the Category to a separate entity, that would consist of title, skill level, date and notes. That is the right way, and it will move out all the warnings. You pupils will have one-to-many relationship with the category—one pupil could be in many categories—that's it.