Can I have query get NPM(i.e, interface and node) related data by using queyXML()?

Hi ,

   I am trying get Network Performance related monitoring data from server using Orion SDK'squeryXML() method.

Here I have Interface, Node and InterfaceTraffic tables in Orion SDK's data base.

What are tables need to join to prepare the query to get data?.

what is the relationship between these three tables above mentioned.

Please help on this.  It will be  much appreciated .

Thanks .