The automatic maintenance of the database involves tools to simplify your administration tasks. You can configure this option anytime after you create the database.
Basically, you define maintenance schedules:
online: Period of low activity to allow for runstats
offline: Period when there is no activity (no user connecting), for backups and reorgs
You also define maintenance activities:
backups: DB2 determines if a backup is needed and schedules it during maintenance windows (offline)
reorgs: Used to reorganize tables for optimal table space use (offline)
runstats: Makes sure DB2 has a quantitative view of data for its optimizer to produce best results (online)
You can have configured notifications on maintenance jobs.