Here is an example of how to use the NODENUMBER function.
If CORPDATA.EMPLOYEE is a distributed table, then the node number for each row and the employee name is returned.
SELECT NODENUMBER(CORPDATA.EMPLOYEE), LASTNAME FROM CORPDATA.EMPLOYEE
OPNQRYF FILE((CORPDATA/EMPLOYEE)) FORMAT(FNAME) MAPFLD((NODENAME '%NODENUMBER(1)') (LNAME '1/LASTNAME'))