[postgis-users] "non intersecting node" error when using st_node ?!

[Sandro Santilli]

On Tue, Sep 27, 2016 at 07:55:46AM -0500, Mathias Versichele wrote:
> Hi all,
> 
> I've been struggling with "non intersecting node" issues when trying to run
> st_node, which seems weird to me as st_node is supposed to fix these issues
> in the first place, right ?
> 
> The following table dump illustrates the problem: https://we.tl/d3WwOv2AFv
> 
> When running the following query:
> 
> select st_node(st_collect(geom)) from input_geoms;
> 
> I get the following error:
> 
> ERROR:  GEOSUnaryUnion: TopologyException: found non-noded intersection
> between LINESTRING (1.0708e+06 786844, 1.07094e+06 786875) and LINESTRING
> (1.07097e+06 786883, 1.0708e+06 786844) at 1070922.7377618756
> 786871.60839152802
> 
> The input geoms are already snapped to 10meters precision.
> 
> Help very much appreciated on how to fix this issue.

The message reveals a robustness issue. Noding simply failed.
Worth filing a ticket for this. Include output from
postgis_full_version and a minimal version of the table dump.

--strk;