10 Flyway Best Practices

Flyway is an open-source database migration tool that helps developers and DevOps teams manage database changes. It is a popular tool for managing database migrations and is used by many organizations.

However, Flyway can be difficult to use if you don’t follow best practices. In this article, we will discuss 10 Flyway best practices that will help you get the most out of the tool. We will cover topics such as version control, naming conventions, and more. By following these best practices, you can ensure that your database migrations are successful and your database is always up-to-date.

1. Use versioned migrations

Versioned migrations allow you to track the changes that have been made to your database over time. This makes it easier to roll back any changes if something goes wrong, and also helps ensure that all of your databases are in sync with each other.

Versioning also allows you to easily identify which version of a migration is currently running on a particular database. This can be especially useful when debugging issues or trying to understand why certain data is present in one environment but not another.

Finally, versioning ensures that Flyway will only run migrations that haven’t already been applied to the database. This prevents accidental re-running of migrations, which could lead to unexpected results.

2. Keep migration scripts in a single directory

When you keep all of your migration scripts in a single directory, it makes them easier to find and manage. It also helps ensure that the order of execution is correct since flyway will execute scripts in alphabetical order. This can be especially important when dealing with complex migrations that require multiple steps.

Finally, keeping all of your migration scripts in one place allows for better version control. You can easily track changes over time and roll back any unwanted changes quickly and easily.

3. Name your migration scripts using the following pattern: V1__Description.sql

The V1 part of the name is used to indicate the version number of the migration script. This allows Flyway to keep track of which scripts have been applied and in what order. The Description part of the name should be a short description of what the script does, so that it’s easy to identify when looking at the list of migrations.

Using this naming convention makes it easier for developers to quickly identify which scripts need to be run and in what order. It also helps ensure that all scripts are properly tracked and can be easily rolled back if needed.

4. Always use transactions

Transactions ensure that all of the changes made to your database are either applied or rolled back in one go. This means that if something goes wrong during a migration, you won’t end up with an inconsistent state in your database.

Using transactions also helps improve performance by reducing the number of round trips between the application and the database. Transactions can be used for both single-statement migrations as well as multi-statement migrations.

Finally, using transactions ensures that any data integrity checks (such as foreign key constraints) are enforced before the migration is completed. This helps prevent errors from occurring due to invalid data being inserted into the database.

5. Don’t execute DDL statements directly on production databases

When you execute DDL statements directly on production databases, it can cause unexpected issues. For example, if the statement fails to run properly, it could leave your database in an inconsistent state and lead to data loss or corruption. Additionally, executing DDL statements directly on production databases can also be difficult to track and audit, making it harder to troubleshoot any problems that arise.

Instead of executing DDL statements directly on production databases, use Flyway’s migration scripts. This will ensure that all changes are tracked and audited, and that they are applied consistently across all environments.

6. Avoid mixing SQL and Java code

When you mix SQL and Java code, it can be difficult to maintain the database schema. This is because changes in the Java code may require corresponding changes in the SQL code, which can lead to errors or inconsistencies. Additionally, mixing SQL and Java code makes it harder for developers to understand what’s going on with the database schema.

To avoid these issues, use flyway migrations instead of mixing SQL and Java code. Flyway migrations are written in pure SQL, so they’re easy to read and maintain. Plus, they make it easier to track changes over time and ensure that your database schema is always up-to-date.

7. Apply schema changes to all environments at once

When you apply schema changes to only one environment, it can lead to inconsistencies between environments. This can cause problems when deploying applications or running tests in different environments. It also makes it difficult to track down and fix any issues that arise due to the differences in schemas.

By applying schema changes to all environments at once, you ensure consistency across your environments. This helps reduce errors and makes it easier to troubleshoot any issues that may arise. Additionally, it allows for more efficient deployments and testing since there is no need to make multiple changes in each environment.

8. Make sure that Flyway is always up-to-date with the latest database state

When Flyway is not up-to-date, it can lead to inconsistencies between the database and application code. This can cause errors when running queries or performing other operations on the database. Additionally, if you are using version control for your database changes, then having an outdated Flyway state will make it difficult to track which changes have been applied and which ones haven’t.

To ensure that Flyway is always up-to-date, you should regularly run a migration script to update the database schema. You should also set up automated processes to check for any new migrations that need to be applied. Finally, you should use version control to keep track of all database changes so that you can easily roll back to a previous version if needed.

9. Test your migrations before deploying them

When you deploy a migration, it’s important to make sure that the changes are applied correctly and don’t cause any unexpected issues. Testing your migrations before deploying them ensures that they will run as expected when deployed in production. This can save you time and money by avoiding costly mistakes or downtime due to failed deployments.

Testing your migrations also allows you to identify potential problems early on, so you can address them before they become an issue. Additionally, testing helps ensure that all of your migrations are compatible with each other, which is essential for maintaining data integrity.

10. Use repeatable migrations for data fixes

When you use repeatable migrations, you can make sure that any data fixes are applied consistently across all environments. This helps to ensure that the same data is present in each environment and reduces the risk of errors or inconsistencies due to manual intervention. Additionally, it makes it easier to track changes over time and roll back any changes if necessary.

Repeatable migrations also help to reduce the amount of code needed for a given task, as they allow you to reuse existing migration scripts instead of writing new ones from scratch. This saves time and effort, and ensures that your database remains consistent and up-to-date.