"An important feature of transactional databases like SQLite is "atomic commit". Atomic commit means that either all database changes within a single transaction occur or none of them occur. With atomic commit, it is as if many different writes to different sections of the database file occur instantaneously and simultaneously. Real hardware serializes writes to mass storage, and writing a single sector takes a finite amount of time. So it is impossible to truly write many different sectors of a database file simultaneously and/or instantaneously. But the atomic commit logic within SQLite makes it appear as if the changes for a transaction are all written instantaneously and simultaneously."