Geometry Cleaner
Self-Intersections in simple feature geometries usually lead to problems in further processing of PostGIS data. Thus, a shape, as it is shown below in the image indeed saved in PostGIS, but geometric analysis can be carried out erroneous geometries.
- Invalid, self intersecting polygon
The solution to the problem provides the Postgres function cleangeometry (geometry) which can be downloaded here. This feature has been adjusted for self-intersecting polygons such that separated after correcting all overlapping objects and converted them into a multi-objects. In the figure below are for illustrative purposes, the two sub-polygons of the new multi-polygon pulled apart.
To clean up self-intersecting polygons and lines the Postgres function cleangeometry() have to be created in the postgres database with: psql-d mydb-f cleanGeometry.sql To clean up the tables with incorrect geometries, an update of the geometry-objects can be made with: update myTable set the_geom = cleangeometry(the_geom)