Database Implementation

Database migrations automate schema changes through versioned SQL scripts. Use Flyway to version and execute migrations sequentially, ensuring reproducible schema evolution across development, testing, and production environments with rollback capabilities.

ORMs like Exposed map entity classes to database tables automatically. Define entities with properties, configure column types and constraints, then generate or hand-write migrations to create the underlying schema and validate entity-to-table alignment.

Database indexes accelerate query performance on frequently searched columns. Plan indexes during schema design, define primary and foreign key constraints to enforce data integrity, then validate indexing strategy through query performance testing.

Yes, Flyway and ORMs work together in complementary roles. Flyway manages schema migrations and version control; the ORM handles entity mapping and query generation. Coordinate both tools to ensure schema and entity definitions stay synchronized.

Test migrations by running them against isolated test databases and verifying schema conformance. Test repository queries against seeded data to catch logic errors. Automate tests across development, staging, and production-like environments before deployment.

Migration failures halt execution to prevent partial schema changes. Flyway supports rollback strategies through versioned undo scripts or manual recovery procedures. Plan rollback logic during migration design and test it in staging environments.