DB Motivating Example – Police IT
Bill Hayden is suspected of masterminding a nationwide terrorist organisation.
As well as looking up his past database records, the investigators (special terrorism unit) subscribe, in all 43 police counties, to advertised database update events specifying his name as an attribute.
Note inter-domain naming and access control.
Triggers are set in the databases so that any future records that are made, relating to his movements and activities, will be published and notified automatically and immediately to those authorised to investigate him.