How to see raw sql in core data execution

In XCode, go to scheme list and select edit scheme. Pick 'Run' scheme and select arguments.
In 'Arguments passed on launch' add the following “-com.apple.CoreData.SQLDebug 1”.
Now when you run the app you will see the sql execution status in the output window.

Source - http://www.raywenderlich.com/934/core-data-on-ios-5-tutorial-getting-started