--- a/wamos.sql	Mon May 07 22:21:17 2018 +0200
+++ b/wamos.sql	Mon May 07 22:31:12 2018 +0200
@@ -95,8 +95,6 @@
        rb char(2) NOT NULL REFERENCES countries, -- from rb_lb in interface
        lb char(2) NOT NULL REFERENCES countries, -- from rb_lb in interface
        responsible_country char(2) NOT NULL REFERENCES countries,
-       riverbed varchar NOT NULL REFERENCES riverbed_materials,
-       -- XXX: should be 'natsur' according to IENC Encoding Guide M.4.3
        revisiting_time smallint NOT NULL,
        surtyp varchar NOT NULL REFERENCES survey_types,
        -- XXX: Not an attribut of sounding result?
@@ -114,6 +112,14 @@
 CREATE TRIGGER bottleneck_date_info BEFORE UPDATE ON bottlenecks
        FOR EACH ROW EXECUTE PROCEDURE update_date_info();
 
+CREATE TABLE bottlenecks_riverbed_materials (
+       bottleneck_id varchar REFERENCES bottlenecks,
+       riverbed varchar REFERENCES riverbed_materials,
+       -- XXX: should be 'natsur' according to IENC Encoding Guide M.4.3
+       PRIMARY KEY (bottleneck_id, riverbed)
+       );
+
+
 CREATE TABLE vertical_references (
        vertical_reference varchar PRIMARY KEY
        );