Prisma 3.9.0 introduces two new low-level Preview commands — `migrate diff` and `db execute` — to improve the developer experience when troubleshooting failed schema migrations. `migrate diff` compares any two schema sources (live database, Prisma data model, migration history, or empty) and outputs a human-readable summary or executable SQL. `db execute` runs SQL against a database, and the two commands can be piped together to detect and resolve schema drift. The post also explains why Prisma intentionally avoids down migrations (rollbacks give a false sense of security) and transactional DDL (not universally supported, costly at scale), recommending instead small, non-breaking, additive migrations using the expand-and-contract pattern.
