Gated Schema Deployments` is a new feature introduced by PlanetScale to simplify and streamline the process of making changes to a sharded database. The deployments can now be thought of as atomic operations, reducing complexity and allowing multiple schema changes to be made simultaneously without disrupting the database. This feature addresses two main challenges: multi-dimensional deployments, where multiple changes are applied in parallel, and multi-shard deployments, where different shards have different schemas. With `Gated Deployments`, users can now choose when to apply changes, giving them more control over their schema migrations, and the deployment process is now more closely tied to data changes, ensuring that no change is reflected in production until it's fully complete.