Is there a mechanism to detect a design change in the datamodel for an iPad application?

I am building a new application and fully expect the datamodel to change in the future. I was wondering if t开发者_开发知识库he existing constructs have a versioning attribute that can be used for detecting a change that will trigger a migration.

I have found this by exporting the SQLite DB that I found in the simulator's Application-Document directory.

ls  ~/Library/Application\ Support/iPhone\ Simulator/4.3/Applications/64A2DBF0-CBCC-4975-8366-0EC800D1D1F7/Documents/MyApplication.sqlite

Partial dump:

"Z_VERSION","Z_UUID","Z_PLIST"
"1","A6722D4A-3DBB-4D48-8356-D173A1C288AA","bpl .... (etc)

Is this value managed in the NSManagedObject ??