{"id":"system-has-no-undo-at-any-layer","text":"No layer in the system can reverse a completed operation: the WAL stores only new values with no before-images (making rollback structurally impossible), and transaction abort is a status-flag change that leaves all written versions on disk, meaning neither the storage layer nor the logical transaction layer supports undo.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"explanation":{"steps":[{"node":"system-has-no-undo-at-any-layer","truth_value":"IN","reason":"premise"}]}}