Managing Elixir Migrations and Preventing Orphaned Data

The article by Dorian Karter emphasizes the critical role of the `on_delete` attribute in Elixir's Ecto migrations, which specifies what should happen to child records when their parent record is deleted. The default `:nothing` action could lead to orphaned records, which is undesirable. Karter elaborates on other options like `:delete_all`, `:nilify_all`, and `:restrict`, each with different behaviors appropriate for specific scenarios. The author also explains that behavior can differ between databases, citing differences between Postgres and SQLite. Furthermore, the article illustrates common use-cases and potential pitfalls, urging developers to carefully consider the direction of relationships and the specific implementation details of their database of choice. Ultimately, Karter advocates for thorough understanding and careful testing of migrations, considering soft deletions and data anonymization as strategies for certain use cases, in order to maintain data integrity.