[postgis-tickets] [PostGIS] #4182: Unexpected TopologyException during ST_Union aggregate function with valid polygons

[PostGIS]

#4182: Unexpected TopologyException during ST_Union aggregate function with valid
polygons
----------------------+---------------------------
 Reporter:  blaggner  |      Owner:  pramsey
     Type:  defect    |     Status:  new
 Priority:  medium    |  Milestone:  PostGIS 2.4.6
Component:  postgis   |    Version:  2.3.x
 Keywords:            |
----------------------+---------------------------
 When aggregating geometries of a large table (53.5 Mio. polygons) with
 ST_Union grouped by an ID column (resulting rows at the end: 2958073),
 ST_Union threw an error:
 ERROR:  GEOSUnaryUnion: TopologyException: found non-noded intersection
 between LINESTRING (3.3987e+06 5.33572e+06, 3.3987e+06 5.33572e+06) and
 LINESTRING (3.3987e+06 5.33572e+06, 3.3987e+06 5.33572e+06) at
 3398704.354833886 5335719.4814453134
 I tested the geometries of the table with ST_IsValid and there were no
 invalid geometries.
 With the help of a wrapper function, I was able to identify the rows that
 were causing the problem (see attached data). However, when trying to
 reproduce the error on the selected geometries, ST_Union was able to
 aggregate the geometries without a problem.

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/4182>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.