Summary

This hour introduced you to the continuum of Core Data migration techniques and tools. The data model in your app must be compatible with the data model used to create the persistent store. This hour helped you understand the ways in which database schema changes do and do not create incompatibilities.

Q&A

Q.	Why is Core Data migration considered a continuum?
A.	It is customizable and consists of tools and techniques that handle incompatibilities of different types and scales.
Q.	Is there one problem that many people have with data migration?
A.	Whether you are talking about Core Data or other technologies, many developers are nervous about data migration. You see signs of this in many databases in which fields have been repurposed and Postal Code becomes something like Preferred Shipper without having its field name changed. The takeaway from Core Data’s continuum of migration is not to be afraid: There are many simple ways to migrate your data model and make it easy for people to use and maintain.