Ways outside of municipal boundries are lost

[PeterBrodersen]

As we cut up roads based on municipality polygons we lose roads not in any municipality.

We currently cut up roads in [import/aggregate.sql] using ST_Intersects(). This is matched against every municipality geometry. The purpose is to split up roads that span several municipalities, not remove those who are outside every municipality.

Example: Christian D. IV's Bro

After the grouping and intersection only three tiny blue points appear (those on the boundary).

[PeterBrodersen]

Requests using ST_Difference() seems extremely slow. Also, ST_CoveredBy() to only get ways not part of any municipality is similarly slow.

-- Places outside?
SELECT name, ST_Difference(st_transform(ST_COLLECT(geom), 4326), (select ST_Union(wkb_geometry) from osmetymology.municipalities))
FROM osmetymology.osm_ways ow
ST_INTERSECTS(st_transform(ow.geom,4326), m.wkb_geometry)
WHERE name IS NOT NULL AND ("name:etymology" IS NOT NULL OR "name:etymology:wikipedia" IS NOT NULL OR "name:etymology:wikidata" is not NULL)
and not ST_CoveredBy(st_transform(geom, 4326), (select ST_Union(wkb_geometry) from osmetymology.municipalities))
and name like '%bro'
GROUP by name, "name:etymology", "name:etymology:wikipedia","name:etymology:wikidata"