Intro to Migrations

Data migrations are processes that involve changing the shape of data in databases, typically through schema and data changes, and can be performed in two primary ways: offline and online migrations. Offline migrations require stopping the application from serving traffic to implement schema changes, which can lead to downtime and potential rollback challenges if errors occur. In contrast, online migrations allow the application to continue serving requests while data is updated asynchronously, although this method introduces complexities such as handling both old and new data formats simultaneously. Best practices for managing migrations include creating new fields instead of altering existing ones, avoiding data deletion unless necessary, and using strategies like dual writing or reading to safely transition between old and new data formats. The use of a tool like Convex can facilitate schema validation and guide developers through the process, ensuring that changes can be rolled back or adapted without disrupting the application.