3

I'm using pgrouting shortest_path_astar with a complicated cost function. It gives back the edges, vertices and costs. I would like to get the total distance of this shortest path (i.e., the sum of lengths of edges, not the sum of costs of edges).

For now, I use:

SELECT SUM(t2.length) FROM (
    SELECT edge_id FROM shortest_path_astar(..., TRUE, TRUE)
) as t1,
routing.edges as t2 where t1.edge_id = t2.edge_id

Is it the most efficient way to get the distance? I need to run this query many times and I want to be sure to do it in the fastest way.

2
  • You could try if a LEFT JOIN is faster, but I think the PostGIS query analyzer should do a good job and figure it out anyway.
    – underdark
    Aug 11, 2012 at 9:52
  • Don't use such an ancient version of pgRouting, especially if you want to run this many times. In that case you can use 1:n or even n:n shortest path queries: docs.pgrouting.org/latest/en/pgr_dijkstra.html#pgr-dijkstra
    – dkastl
    Jul 15, 2018 at 10:04

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