But... in not less than two scenarios this option is helpful: backfilling far more bars after options change (any time you enlarge 'quantity of bars to load' in File->Database Configurations dialog You need to pressure backfill for symbols that were backfilled Earlier with smaller variety of bars) Responsible data feeds https://andresttsqs.blogoscience.com/41452671/the-basic-principles-of-amibroker-data-feed