No Transaction Processing (or "non-transaction files") is the simplest transaction level. This mode is appropriate for temporary files and for non-critical data.
The server does not guarantee that unwritten updated data and index cache pages are backed by a persistent copy on disk, so non-transaction files are not recoverable in the event of an abnormal server termination. In such a situation a non-transaction file is in an unknown state because an unknown number of updates may have not yet been written to disk at the time of the abnormal server termination.
This mode does not provide recoverability. It is best suited for temporary data that does not need to be committed to permanent storage. If it is used for critical data, data integrity must be protected by other means.