Name

ST_Node — Node a set of linestrings.

Synopsis

geometry ST_Node(geometry geom);

Description

Fully node a set of linestrings using the least possible number of nodes while preserving all of the input ones.

This function supports 3d and will not drop the z-index.

Performed by the GEOS module.

Availability: 2.0.0

Changed: 2.4.0 this function uses GEOSNode internally instead of GEOSUnaryUnion. This may cause the resulting linestrings to have a different order and direction compared to Postgis < 2.4.

Examples

SELECT ST_AsText(
        ST_Node('LINESTRINGZ(0 0 0, 10 10 10, 0 10 5, 10 0 3)'::geometry)
    ) As  output;
output
-----------
MULTILINESTRING Z ((0 0 0,5 5 4.5),(5 5 4.5,10 10 10,0 10 5,5 5 4.5),(5 5 4.5,10 0 3))
        

See Also

ST_UnaryUnion