[pgrouting-users] Many to many routing and traffic assignment

Dear pgrouting users,
I am begginer at using pgrouting and SQL as a whole, but this tool would be very useful for my projects. My task is to perform traffic assignment on the road network of Bulgaria. I use routable map prepared with Osm2po. My start/end points are defined according to the map nodes. Using the code from the example:

SELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_dijkstra('
                SELECT gid AS id,
                         length::double precision AS cost
                        FROM ways',
                30, 60, false, false);