--- a/pkg/controllers/diff.go	Tue Oct 08 10:37:02 2019 +0200
+++ b/pkg/controllers/diff.go	Tue Oct 08 12:10:55 2019 +0200
@@ -63,29 +63,6 @@
 WHERE m.date_info = $2::date AND s.date_info = $3::date
 RETURNING id
 `
-	insertDiffContourSQL = `
-INSERT INTO caching.sounding_differences_contour_lines (
-  sounding_differences_id,
-  height,
-  lines
-)
-SELECT
-  $5,
-  $4,
-  ST_Transform(
-    ST_Multi(
-      ST_CollectionExtract(
-        ST_SimplifyPreserveTopology(
-          ST_Multi(ST_Collectionextract(
-            ST_MakeValid(ST_GeomFromWKB($1, $2::integer)), 2)),
-          $3
-        ),
-        2
-      )
-    ),
-    4326
-  )
-`
 	insertDiffIsoAreasQL = `
 INSERT INTO caching.sounding_differences_iso_areas (
   sounding_differences_id,
@@ -302,12 +279,6 @@
 
 	log.Printf("info: num heights: %d\n", len(heights))
 
-	var stmt *sql.Stmt
-	if stmt, err = tx.PrepareContext(ctx, insertDiffContourSQL); err != nil {
-		return
-	}
-	defer stmt.Close()
-
 	var isoStmt *sql.Stmt
 	if isoStmt, err = tx.PrepareContext(ctx, insertDiffIsoAreasQL); err != nil {
 		return
@@ -326,19 +297,6 @@
 
 	heights = common.DedupFloat64s(heights)
 
-	octree.DoContours(tree, heights, func(res *octree.ContourResult) {
-		if err == nil && len(res.Lines) > 0 {
-			_, err = stmt.ExecContext(
-				ctx,
-				res.Lines.AsWKB2D(),
-				minuendTree.EPSG,
-				contourTolerance,
-				res.Height,
-				id,
-			)
-		}
-	})
-
 	areas := tree.TraceAreas(heights, isoCellSize)
 
 	for i, a := range areas {