Under what condition is deleted record recovery in a database impossible?

• A. If it has had many write operations since the records were deleted
• B. If it has not had any writes since deletion
• C. If the database is read-only from creation
• D. If log backups exist

Answer: (A)

When a row is deleted, the database usually doesn’t erase the bytes right away; it often marks that space as free and leaves the old data on disk until that space is reused. If many write operations happen after the deletion, those storage blocks can be overwritten with new data, destroying the original bytes. Once those bytes are overwritten, the deleted record cannot be recovered because there is no intact data left to reconstruct. Log backups or backups can help recover data up to the point of their capture, but they can’t resurrect data that has already been overwritten on disk. If there have been no writes since deletion, the original data may still be recoverable, which is why that scenario doesn’t render recovery impossible.