Fix SQL update logic (patch from 3.6.2)

layers/waterway/update_important_waterway.sql

@@ -0,0 +1,96 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_waterway_linestring;
+DROP TRIGGER IF EXISTS trigger_refresh ON waterway_important.updates;
+
+-- We merge the waterways by name like the highways
+-- This helps to drop not important rivers (since they do not have a name)
+-- and also makes it possible to filter out too short rivers
+
+-- etldoc: osm_waterway_linestring ->  osm_important_waterway_linestring
+DROP MATERIALIZED VIEW IF EXISTS osm_important_waterway_linestring CASCADE;
+DROP MATERIALIZED VIEW IF EXISTS osm_important_waterway_linestring_gen1 CASCADE;
+DROP MATERIALIZED VIEW IF EXISTS osm_important_waterway_linestring_gen2 CASCADE;
+DROP MATERIALIZED VIEW IF EXISTS osm_important_waterway_linestring_gen3 CASCADE;
+
+CREATE INDEX IF NOT EXISTS osm_waterway_linestring_waterway_partial_idx
+    ON osm_waterway_linestring(waterway)
+    WHERE waterway = 'river';
+
+CREATE INDEX IF NOT EXISTS osm_waterway_linestring_name_partial_idx
+    ON osm_waterway_linestring(name)
+    WHERE name <> '';
+
+CREATE MATERIALIZED VIEW osm_important_waterway_linestring AS (
+    SELECT
+        (ST_Dump(geometry)).geom AS geometry,
+        name, name_en, name_de, tags
+    FROM (
+        SELECT
+            ST_LineMerge(ST_Union(geometry)) AS geometry,
+            name, name_en, name_de, tags
+        FROM osm_waterway_linestring
+        WHERE name <> '' AND waterway = 'river'
+        GROUP BY name, name_en, name_de, tags
+    ) AS waterway_union
+);
+CREATE INDEX IF NOT EXISTS osm_important_waterway_linestring_geometry_idx ON osm_important_waterway_linestring USING gist(geometry);
+
+-- etldoc: osm_important_waterway_linestring -> osm_important_waterway_linestring_gen1
+CREATE MATERIALIZED VIEW osm_important_waterway_linestring_gen1 AS (
+    SELECT ST_Simplify(geometry, 60) AS geometry, name, name_en, name_de, tags
+    FROM osm_important_waterway_linestring
+    WHERE ST_Length(geometry) > 1000
+);
+CREATE INDEX IF NOT EXISTS osm_important_waterway_linestring_gen1_geometry_idx ON osm_important_waterway_linestring_gen1 USING gist(geometry);
+
+-- etldoc: osm_important_waterway_linestring_gen1 -> osm_important_waterway_linestring_gen2
+CREATE MATERIALIZED VIEW osm_important_waterway_linestring_gen2 AS (
+    SELECT ST_Simplify(geometry, 100) AS geometry, name, name_en, name_de, tags
+    FROM osm_important_waterway_linestring_gen1
+    WHERE ST_Length(geometry) > 4000
+);
+CREATE INDEX IF NOT EXISTS osm_important_waterway_linestring_gen2_geometry_idx ON osm_important_waterway_linestring_gen2 USING gist(geometry);
+
+-- etldoc: osm_important_waterway_linestring_gen2 -> osm_important_waterway_linestring_gen3
+CREATE MATERIALIZED VIEW osm_important_waterway_linestring_gen3 AS (
+    SELECT ST_Simplify(geometry, 200) AS geometry, name, name_en, name_de, tags
+    FROM osm_important_waterway_linestring_gen2
+    WHERE ST_Length(geometry) > 8000
+);
+CREATE INDEX IF NOT EXISTS osm_important_waterway_linestring_gen3_geometry_idx ON osm_important_waterway_linestring_gen3 USING gist(geometry);
+
+-- Handle updates
+
+CREATE SCHEMA IF NOT EXISTS waterway_important;
+
+CREATE TABLE IF NOT EXISTS waterway_important.updates(id serial primary key, t text, unique (t));
+CREATE OR REPLACE FUNCTION waterway_important.flag() RETURNS trigger AS $$
+BEGIN
+    INSERT INTO waterway_important.updates(t) VALUES ('y')  ON CONFLICT(t) DO NOTHING;
+    RETURN null;
+END;
+$$ language plpgsql;
+
+CREATE OR REPLACE FUNCTION waterway_important.refresh() RETURNS trigger AS
+  $BODY$
+  BEGIN
+    RAISE LOG 'Refresh waterway';
+    REFRESH MATERIALIZED VIEW osm_important_waterway_linestring;
+    REFRESH MATERIALIZED VIEW osm_important_waterway_linestring_gen1;
+    REFRESH MATERIALIZED VIEW osm_important_waterway_linestring_gen2;
+    REFRESH MATERIALIZED VIEW osm_important_waterway_linestring_gen3;
+    DELETE FROM waterway_important.updates;
+    RETURN null;
+  END;
+  $BODY$
+language plpgsql;
+
+CREATE TRIGGER trigger_flag
+    AFTER INSERT OR UPDATE OR DELETE ON osm_waterway_linestring
+    FOR EACH STATEMENT
+    EXECUTE PROCEDURE waterway_important.flag();
+
+CREATE CONSTRAINT TRIGGER trigger_refresh
+    AFTER INSERT ON waterway_important.updates
+    INITIALLY DEFERRED
+    FOR EACH ROW
+    EXECUTE PROCEDURE waterway_important.refresh();