Where does the action and timestamp column come from?

The action and timestamp columns are typically part of an audit trail used to track changes or events in a database. They are often added automatically by database triggers, application code, or an ORM layer. When a row is inserted, updated, or deleted, a trigger can insert a record into an audit table that includes the action type (INSERT, UPDATE, DELETE), the timestamp of the change, and optionally the user who performed the action. This allows for historical tracking, debugging, and compliance. In many systems, these columns are added via a base entity class or a mixin that all tables inherit from, ensuring consistency across the schema.