This article provides relevant information regarding differential updates for the WebGrade database.
GFI WebMonitor makes use of the differential update system for the WebGrade database; this means that the whole database needs to be downloaded in the first update. Subsequent updates would require only a differential update file. The size of each differential update file is relatively small, averaging less than 600 KB.
If GFI WebMonitor does not update the WebGrade database for approximately a week, it will automatically download the full update.