This document discusses database migrations and compares the frameworks Flyway and Liquibase. It outlines the challenges of frequent database updates in agile development and how automated database migrations address this issue. Flyway and Liquibase are both open source Java frameworks that allow deterministic migrations from one database version to another. The document demonstrates each tool and highlights their differences, such as Flyway using SQL files versus Liquibase's XML format. It concludes with recommendations to migrate databases on startup and focus on processes over framework features.

1. Database migrations
Flyway and Liquibase
Lars Östling
lars.ostling@jayway.com
@larsostling

2. Agenda
• Database migrations
• Flyway
• Liquibase
• Conclusions

3. Back in the day…
• Big up-front design
• Long development cycles
• Scary updates

4. In an agile world…
• Short iterations
• Continuous integration /
delivery / deployment
• Delivery pipe-lines
• We do it for code …
• … what about the database?

6. The challenge
• Frequent database updates
• Managing multiple sql files
• What has been applied and
what has not?
• Keeping code and database
in sync …
• … throughout all
environments

7. The solution
Automated database migrations:
• Recreate database from
scratch
• Make it clear at all times what
state a database is in
• Migrate in a deterministic way
from current version of the
database to a newer one

9. What is Flyway?
• Agile database migration framework for Java
• Open Source Apache 2.0 license
• Started in 2010
• Status ‘Adopt’ on thoughtworks technology radar
• http://www.flywaydb.org

10. Demo
https://github.com/larsostling/
database-migrations-demo

11. Short recap
• Schema version table
• Convention over configuration
• Sql and java migrations
• Supereasy to setup

13. What is Liquibase?
• Agile database migration framework for Java
• Open Source Apache 2.0 license
• Started in 2006
• http://www.liquibase.org

14. Demo
https://github.com/larsostling/
database-migrations-demo

15. Short recap
• Uses structured DSL to
describe database changes
• Databasechangelog table
• Supports rollback
• generateChangeLog

16. Flyway vs. Liquibase
• SQL vs. XML
• Multiple files vs. single file
• No rollback vs. rollback
• KISS vs. less KISS

17. Some advice
• Migrate on application startup
• Change sets do not change
• People and processes

18. Lessons learned
• Stop worrying about database
changes
• Pick a framework and start
using it

19. Q & A

20. Thanks!
Lars Östling
lars.ostling@jayway.com
@larsostling