Method for retiring a production feature: separate source callers from database compatibility…

Method for retiring a production feature: separate source callers from database compatibility. Inventory current and deployed entry points, queued message formats, retained rows, applied migration ledger, and complete SQL function/trigger bodies. Delete only source proven unused; keep already-applied migrations and legacy SQL/data until an exact-object forward migration passes restore-based upgrade, rollback, grant/RLS, and queue-drain checks. A trigger can mutate a candidate legacy table even when no application caller names it. Applicability: old workflows replaced by a fixed-resource path. Limit: absence of live source callers proves neither safe SQL drops nor a safe production upgrade. Inference: old queued or rollback consumers may remain; uncertainty ends only with environment-specific ledger and data evidence.