Classifies every DDL and DML statement in a database migration into an eight-category operation taxonomy (additive, backwards-compatible alter, locking, lock-escalating, breaking, data-loss, unsafe default, index-missing foreign key) and assigns a Critical, Warning, or Info severity justified by the lock mode and table-rewrite behavior the target engine actually performs. Records where PostgreSQL and MySQL/InnoDB diverge for the same logical statement, and where behavior is version-gated (PostgreSQL 11 removed the table rewrite for a constant DEFAULT; MySQL 8.0.12 made ADD COLUMN instant). Use when a migration file appears in a diff or a review queue and someone must decide, before it reaches a production-sized table, which statements are safe and which will stall writes or destroy data.