SELECT distinct ST_AsText((ST_Intersection(ST_Buffer(a.geom, 0.2, 'endcap=round join=round'), ST_ExteriorRing(b.geom)))),a.elemid,b.elemid FROM "Line" as a,"Polygon" as b WHERE st_Intersects(a.geom, b.geom)

SELECT distinct ST_AsText((ST_Intersection(ST_Buffer(ST_ExteriorRing(a.geom), 0.2, 'endcap=round join=round'), ST_ExteriorRing(b.geom)))), a.elemid, b.elemid FROM "Polygon" as a,"Polygon" as b WHERE st_Intersects(a.geom, b.geom) and a.id != b.id;