Validation and Cleaning

{: .no_toc }

TOC {:toc}

Constraint to Validate Geometry column

https://gis.stackexchange.com/questions/1060/what-are-the-implications-of-invalid-geometries https://gis.stackexchange.com/a/11234/14766

ALTER TABLE public.my_valid_table
  ADD CONSTRAINT enforce_valid_geom CHECK (st_isvalid(geom));

Remove Ring Self-Intersections / MakeValid

https://gis.stackexchange.com/questions/15286/ring-self-intersections-in-postgis The question and standard answer (buffer(0) are fairly mundane. But note the answer where the user uses MakeValid and keeps only the result polygons with significant area. Might be a good option to MakeValid?

Remove Slivers

https://gis.stackexchange.com/questions/289717/fix-slivers-holes-between-polygons-generated-after-removing-spikes

Remove Slivers after union of non-vector clean Polygons

https://gis.stackexchange.com/questions/351912/st-union-of-set-of-polygons-result-in-polygon-with-very-small-holes

Gives outline for function cleanPolygon but does not provide source

Remove Spikes

https://gis.stackexchange.com/questions/173977/how-to-remove-spikes-in-polygons-with-postgis

Solutions

Some custom code implementations:

https://trac.osgeo.org/postgis/wiki/UsersWikiExamplesSpikeRemover

https://gasparesganga.com/labs/postgis-normalize-geometry/

Remove vertices along straight edges

https://gis.stackexchange.com/questions/15127/how-to-rectify-the-walls-of-buildings-in-postgis

Solution

Simplify the polygon with a very small distance tolerance, using one of: