Virtuoso scheduler allows an arbitrary SQL command to be run at certain intervals.

The scheduler process wakes up every n minutes, scans the SYS_SCHEDULED_EVENT table and executes each command which applies to the current time. Note that overdue commands are executed only once.

There is a virtuoso.ini parameter "SchedulerInterval" under Parameters section which defines the scheduler wake-up interval. Set this to 0 (the default) to disable the scheduler.