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I’ll start the ball rolling with a few wishes for CoreData. I’ll number them CDMWnn - U2 please. Keith


CDMW1: Friendlier error messages (Yes:3 No:0)

Rather than stuff like “An error occurred whilst saving” or “An uncaught exception was raised”.

For Example: Compile and run the example for CoreData/TilePuzzle. Then change TILE_GRID_SIZE from 3 to 4, recompile and run again without first deleting /user/library/application support/timepuzzle.xml.

CDMW2: Easier Version Control and Maintenance for upgrades to the Managed Object Model. (Yes:5 No:0) Yes, at WWDC 2005 the Core Data Team recognize that migrating to a new model is a “very difficult task”, and even recognize that they do not have any solution for the moment to ease it…


This is greatly simplified in 10.5 where you can perform almost automatic migration. I’d say that Apple definetly has listened.


CDMW3: Fast batch unfaulting of SQLite data. (Yes:1 No.0)

Maybe simply a fast migration to an InMemoryStore?


See “Batch Faulting and Pre-fetching with the SQLite Store”, a subsection of http://devworld.apple.com/documentation/Cocoa/Conceptual/CoreData/Articles/cdPerformance.html. )


CDMW4: An Audit Trail that records all permanent changes made in a user session. (Yes:2 No:0)

So changes can be rolled back in a subsequent session. Also useful to report changes made to the database during a session or over a specified period of time by a particular user.

CDMW5: Support for ordered to-many relationships. (Yes:3 No:0)

I voted yes, but I think it might already be in there - take a look at http://developer.apple.com/documentation/Cocoa/Conceptual/ModelObjects/Articles/moAccessorMethods.html#//apple_ref/doc/uid/TP40002132 - of course, this is only if you maintain the ordering yourself; it would be much nicer if CoreData did it for you.


CDMW6: Performance improvments when fetching SQLite data. (Yes:1 No.0)

Official answer from apple is 25,000 objects / seconds on a 2x2Ghz G5 with tons of ram. On my powerbook 1.5Ghz it is about 10,000 objects / seconds which is too slow. Many fetch requests takes more than 5 seconds to execute and return the fetched data.


CDMW7: Autoincrementing Attributes. ( Yes:2 No.0) its a pain writing a value that goes up 1 for every entity created. —- Maybe write an NSManagedObject subclass that maintains a key that’s autoincremented when an entity is created? Shouldn’t be too hard to do.


CDMW8: Remote stores

Being able to create a Core Data model for a remote DB and then slap a bindings-enabled interface ontop of it would be great! /Erik Aderstedt