When configuring the Discovery Online task, you can further specify how the task updates the relevant data.
When 'Force Complete Update' is unticked, the Discovery Online task updates the catalogue records in batches each time it runs.
With this option ticked, the task attempts to update all records in one go. Only tick this option if you are not going to be using your library system at the same time as the task is running as it will put a lot of strain on the performance of your system and may slow down the daily use of your library.