--- a/schema/gemma.sql	Fri Oct 12 09:36:46 2018 +0200
+++ b/schema/gemma.sql	Sat Oct 13 14:26:40 2018 +0200
@@ -286,11 +286,21 @@
     -- This table allows linkage between 1D ISRS location codes and 2D space
     -- e.g. for cutting bottleneck area out of waterway area based on virtual
     -- distance marks along waterway axis (see SUC7).
-    CREATE TABLE distance_marks (
+    CREATE TABLE distance_marks_virtual (
         location_code isrs PRIMARY KEY,
         geom geography(POINT, 4326) NOT NULL,
+        related_enc varchar(12) NOT NULL
+    )
+
+    CREATE TABLE distance_marks (
+        country char(2) NOT NULL REFERENCES countries,
+        hectom int NOT NULL,
+        geom geography(POINT, 4326) NOT NULL,
+        -- include location in primary key, because we have no fairway code:
+        PRIMARY KEY (country, hectom, geom),
         catdis smallint NOT NULL REFERENCES catdis,
-        position_code char(2) NOT NULL REFERENCES position_codes
+        position_code char(2) NOT NULL REFERENCES position_codes,
+        related_enc varchar(12) NOT NULL
     )
 
     -- A table to help geoserver serve the distance marks as WFS 1.1.0.
@@ -299,10 +309,9 @@
     CREATE VIEW waterway.distance_marks_geoserver AS
         SELECT location_code::VARCHAR,
                geom::Geometry(POINT, 4326),
-               catdis,
-               position_code,
+               related_enc,
                (location_code).hectometre
-            FROM waterway.distance_marks
+            FROM waterway.distance_marks_virtual
 
     CREATE TABLE sections_stretches (
         id varchar PRIMARY KEY,