domoticz tables and mysensors

[ebioz]

Hi,
i am using mysensors on 3 arduinos that are collecting data with various sensors and managing the watering of my garden. Data is collected by domoticz on a RPI.
I am trying to get the data from domoticz to send it to another system that will allow to store it for a long time and external to my home as i don't want to open domoticz itself on internet.
I choose to pull the DB every minute to get last updated data. (bad idea ? better idea ?)

And domoticz database is far to be simple ... or logic.
I started with the table deviceStatus that have all the collected metrics. But i can't find the link between the table and the table my sensorChilds : how can i know that a device in deviceStatus is link to a node and child ?
i spent hours looking for the link and was not able to find how domoticz link it in the DB....

Thanks for your help.