CockroachDB offers features that make it easy to support applications in multiple regions. The new feature, Online Primary Key Changes, allows users to upgrade their application from single-region to multi-region with zero downtime. This blog post discusses the use cases and benefits of this feature. It provides examples on how to modify a primary key and demonstrates an entire MovR workload conversion to a multi-region cluster. The feature helps developers create multi-region applications, allowing them to grow their application from single-region to multi-region without downtime.