Pgrouting: Visualizing analyzegraph ring geometries

Question

I have a sample network that I analyzed using pgr_analzyeGraph. The outputs shows that I have 3 ring geometries. How do i get which nodes is part of the ring geometries?

The official document only shares how to see dead ends and where potential gap problems exist. Need to pinpoint where the ring geometries exist at in the tables.

Answer 1

Search for line segments with same source and target id in your data. You possibly would get them

Answer 2

Search for closed LINESTRING geometries in your network:

SELECT ST_IsClosed(geom), geom 
FROM line_network_table
WHERE ST_IsClosed(geom) = 'true';

ST_IsClosed(geometry g);

Description: Returns TRUE if the LINESTRING's start and end points are coincident.