--- a/wamos.sql	Fri Jun 01 18:37:31 2018 +0200
+++ b/wamos.sql	Fri Jun 01 19:12:31 2018 +0200
@@ -159,17 +159,27 @@
        distance_mark_function varchar(8) PRIMARY KEY
        );
 
+CREATE TABLE wamos_waterway.position_codes (
+       position_code char(2) PRIMARY KEY
+       -- Use smallint because of fairway availability provided on daily basis?
+       -- Data come from 2015_06_23_RIS_Index_template_v2p0.xlsx,
+       -- sheet "Position_code" or RIS-Index encoding guide?
+       -- XXX: DRC 2.1.7 and 2.2.5 _seem_ to reference the same thing here.
+       -- Clarify!
+       -- TODO: Do we need an attribute "meaning" or so?
+       );
+
 -- This table allows linkage between the 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 wamos_waterway.distance_marks (
        location_code isrs PRIMARY KEY,
-       geom geometry(POINT, 4326),
-       distance_mark_function varchar(8) REFERENCES distance_mark_functions,
-       -- TODO: add relations to stuff provided as enumerations
-       dummy_attrib varchar,
-       "..." varchar
-       -- TODO: add real distance mark attributes (DRC 2.1.7)
+       geom geometry(POINT, 4326) NOT NULL,
+       distance_mark_function varchar(8)
+           NOT NULL REFERENCES distance_mark_functions,
+       -- XXX: attribute "function" in DRC 2.1.7 as well as CATDIS seem
+       -- to encode the same thing as the object code in ISRS location code.
+       position_code char(2) NOT NULL REFERENCES position_codes
        );
 
 CREATE TABLE wamos_waterway.sections_stretches (
@@ -273,11 +283,6 @@
 --
 -- Fairway availability
 --
-CREATE TABLE wamos_fairway.spot_marks (
-       mark_name varchar PRIMARY KEY
-       -- Use smallint because of fairway availability provided on daily basis?
-       );
-
 CREATE TABLE wamos_fairway.levels_of_service (
        level_of_service smallint PRIMARY KEY
        );
@@ -295,7 +300,7 @@
 
 CREATE TABLE wamos_fairway.fairway_availability (
        id int PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
-       position varchar REFERENCES spot_marks,
+       position_code char(2) REFERENCES position_codes,
        bottleneck_id varchar NOT NULL REFERENCES bottlenecks,
        surdat date NOT NULL,
        UNIQUE (bottleneck_id, surdat),