The database BACKUP command produces a transactionally-consistent image of all the data in the database, and can run simultaneously with normal database operations. In a multiplex, the write server performs the database backup while query servers may continue to execute user queries. Because it must trace out the active data in the database, the database backup typically takes longer than an OS-level backup, though it may use less space on the backup media. The backup facility of Sybase IQ does allow most of the backup operation to run in parallel if it can use multiple backup devices, which can significantly speed up backups. For details about running BACKUP, see “Backing up and restoring the multiplex”.