How to Migrate a Database

This article provides a comprehensive overview of database migrations, including terminology, motivation for migrating databases, common pitfalls along with their solutions, and strategic steps to accelerate the migration process. Database migration refers to moving data from one database to another while changing applications to consume data from and write data to the newly-migrated database. Homogeneous database migration involves moving an application and its data from one database to another with the same underlying DBMS, while heterogeneous database migration involves a change in the underlying DBMS engine. The article also discusses best practices for database migrations, such as thinking small, decoupling release from deployment, and feature flagging the data access layer. Additionally, it covers three release strategies: kill switch, progressive release, and strategic release.