I’m evaluating a migration system for database schema changes. If every change includes an ‘apply’ and a ‘revert’ function, can each SQL DDL action truly be undone, ignoring typical data loss issues?
The possibility of reversing every SQL DDL operation depends heavily on how the changes are implemented and the limits of the specific database system. In my experience with migration systems, complex operations, especially those involving modifications to existing structures or dependencies, may have non-reversible elements if certain assumptions about the data are invalidated. Careful planning, extensive testing, and supplementary measures such as backups or intermediate states are essential. Relying solely on a pair of apply and revert functions without such strategies may not always guarantee a full rollback.
i reckon not every ddl action is 100% revertable. even simple changes could have hidden dependencies that make a clean rollback tricky. best to test and expect the occasional manual tweak.
i reckon sometimes its not just about the ddl code but also the env and dependencies. ever seen a weird case where the revert wasn’t clean due to some hidden consquences? what are ur thoughts on handling such tricky parts?
Experience with database schema migration indicates that while many DDL operations might be reversible in theory, practical issues often arise. Even when using a paired apply/revert model, subtle dependencies or system-specific behaviors can result in partial rollbacks. It is important to emphasize robust testing and supplementary backup strategies to handle unexpected complications. My own projects have underscored the need for comprehensive planning to ensure that revert functions are not considered a drop-in solution but rather part of a broader safety net.