The sensors delivered a lot of type of measures
The organization which create sensors
The users who interact with the sensors via different interfaces: REST APIs and WEB UIs. Every user belongs to a single observation.
The observation pushed by the sensor, using a (write-only) REST API. An observation reports a sensor value at a given time.
The fact represents the values of the sensors observations received. Actually, there are two types : counter and dailyStats.
A “counter” fact counts the number of a sensor’s observations received. So for each sensor, there is at mots one “counter” fact.
A “dailyStats” fact counts the number of a sensor’s observations received in one day. Also, it calculates the maximum value, the minimum value and the average value of all the observations’ value in that day. So, for each sensor and for each day, there is at most one “dailyStats” fact.