{"id":"abort-is-status-change-not-disk-rollback","text":"Aborting a transaction in both MVCC and SSI implementations sets a status flag (`_aborted` set or status marker); no disk writes are reversed because uncommitted data never reached disk","truth_value":"IN","source":"entries/2026/05/29/topic-undo-logging-and-steal-policy.md","source_url":"","source_hash":"","justifications":[],"dependents":["system-has-no-undo-at-any-layer","transaction-isolation-fragile-under-restart","transaction-recovery-has-no-crash-path"],"metadata":{"example":"def abort(self, tx):\n    tx._status = \"aborted\"\n    self._aborted.add(tx.tx_id)\n    for v in self._versions[key]:\n        if v.deleted_by == tx.tx_id:\n            v.deleted_by = None  # unmark, no disk undo"},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"abort-is-status-change-not-disk-rollback","truth_value":"IN","reason":"premise"}]}}