I am in the process to implement an AtomicStore subclass to save data in a MySQL DB. The system already works pretty well besides the implementation of fetch-requests. The fetches should include the cached nodes but also fire a "select" on the underlaying SQL db.
I have currently only worked on SubClasses for NSAtomicStore and NSAtomicStoreCacheNode. So running a fetch will only result to search within any cached nodes. As fetched is effectively done on an NSManagedObjectContext instance I would assume that also this class needs an overwrite.
Anyway in my current understanding of Core Data I assumed that anything specific for a "custom store" will be done only in NSAtomicStore (and NSAtomicStoreCacheNode). So I looked for something here will should execute a fetch.
As the SQLite implementation is not avail. in source code I digged a bit into "GnuStep", here a "fetch-method" is injected into the NSAtomicStore. Maybe somebody can point me to the right direction here.
Thus maybe there are some "hidden" interfaces on NSAtomicStore to be overridden or the need to subclass NSManagedObjectContext.