Tried looking in the documentation for PI Interface For Relation Database (RDBMS Via ODBC) to find out more about the distributor tag for each interface. The documentation clearly says the SQL file is to be specified in the InstrumentTag property of the distributor tag, but I could not find anywhere that described what the actual value in the distributor tag represents. I am guessing it must be the number of rows returned by the SQL statement/file or the number of PI tags updated when the script was run. Was wondering if the value is documented somewhere.
