Goal
Provide migration helpers that perform schema changes without taking a write lock for large tables — Postgres ADD COLUMN … DEFAULT … NOT NULL style (fast path on PG 11+), MySQL ALGORITHM=INSTANT where available.
Acceptance criteria
Blueprint.OnlineAddColumn / OnlineDropColumn helpers that emit dialect-correct SQL- Per-dialect docs explaining when the fast path applies
- Migration tests against PG and MySQL covering both code paths
Goal
Provide migration helpers that perform schema changes without taking a write lock for large tables — Postgres
ADD COLUMN … DEFAULT … NOT NULLstyle (fast path on PG 11+), MySQLALGORITHM=INSTANTwhere available.Acceptance criteria
Blueprint.OnlineAddColumn/OnlineDropColumnhelpers that emit dialect-correct SQL