diff --git a/layers/transportation_name/merge_highways.sql b/layers/transportation_name/merge_highways.sql
index c834c17..18e92a9 100644
--- a/layers/transportation_name/merge_highways.sql
+++ b/layers/transportation_name/merge_highways.sql
@@ -1,16 +1,11 @@
 
-DROP TABLE IF EXISTS osm_transportation_name_linestring CASCADE;
-DROP TABLE IF EXISTS osm_transportation_name_linestring_gen1 CASCADE;
-DROP TABLE IF EXISTS osm_transportation_name_linestring_gen2 CASCADE;
-DROP TABLE IF EXISTS osm_transportation_name_linestring_gen3 CASCADE;
-
 -- Instead of using relations to find out the road names we
 -- stitch together the touching ways with the same name
 -- to allow for nice label rendering
 -- Because this works well for roads that do not have relations as well
 
 -- etldoc: osm_highway_linestring ->  osm_transportation_name_linestring
-CREATE TABLE IF NOT EXISTS osm_transportation_name_linestring AS (
+CREATE MATERIALIZED VIEW osm_transportation_name_linestring AS (
 	SELECT
 		(ST_Dump(geometry)).geom AS geometry,
         -- NOTE: The osm_id is no longer the original one which can make it difficult
@@ -35,11 +30,10 @@ CREATE TABLE IF NOT EXISTS osm_transportation_name_linestring AS (
 	    GROUP BY name, highway, ref
 	) AS highway_union
 );
-
 CREATE INDEX IF NOT EXISTS osm_transportation_name_linestring_geometry_idx ON osm_transportation_name_linestring USING gist(geometry);
 
 -- etldoc: osm_transportation_name_linestring -> osm_transportation_name_linestring_gen1
-CREATE TABLE IF NOT EXISTS osm_transportation_name_linestring_gen1 AS (
+CREATE MATERIALIZED VIEW osm_transportation_name_linestring_gen1 AS (
     SELECT ST_Simplify(geometry, 50) AS geometry, osm_id, member_osm_ids, name, ref, highway, z_order
     FROM osm_transportation_name_linestring
     WHERE highway IN ('motorway','trunk')  AND ST_Length(geometry) > 8000
@@ -47,7 +41,7 @@ CREATE TABLE IF NOT EXISTS osm_transportation_name_linestring_gen1 AS (
 CREATE INDEX IF NOT EXISTS osm_transportation_name_linestring_gen1_geometry_idx ON osm_transportation_name_linestring_gen1 USING gist(geometry);
 
 -- etldoc: osm_transportation_name_linestring_gen1 -> osm_transportation_name_linestring_gen2
-CREATE TABLE IF NOT EXISTS osm_transportation_name_linestring_gen2 AS (
+CREATE MATERIALIZED VIEW osm_transportation_name_linestring_gen2 AS (
     SELECT ST_Simplify(geometry, 120) AS geometry, osm_id, member_osm_ids, name, ref, highway, z_order
     FROM osm_transportation_name_linestring_gen1
     WHERE highway IN ('motorway','trunk')  AND ST_Length(geometry) > 14000
@@ -55,9 +49,34 @@ CREATE TABLE IF NOT EXISTS osm_transportation_name_linestring_gen2 AS (
 CREATE INDEX IF NOT EXISTS osm_transportation_name_linestring_gen2_geometry_idx ON osm_transportation_name_linestring_gen2 USING gist(geometry);
 
 -- etldoc: osm_transportation_name_linestring_gen2 -> osm_transportation_name_linestring_gen3
-CREATE TABLE IF NOT EXISTS osm_transportation_name_linestring_gen3 AS (
+CREATE MATERIALIZED VIEW osm_transportation_name_linestring_gen3 AS (
     SELECT ST_Simplify(geometry, 120) AS geometry, osm_id, member_osm_ids, name, ref, highway, z_order
     FROM osm_transportation_name_linestring_gen2
     WHERE highway = 'motorway' AND ST_Length(geometry) > 20000
 );
 CREATE INDEX IF NOT EXISTS osm_transportation_name_linestring_gen3_geometry_idx ON osm_transportation_name_linestring_gen3 USING gist(geometry);
+
+--- Triggers
+
+CREATE OR REPLACE FUNCTION refresh_osm_transportation_name_linestring() RETURNS trigger AS
+  $BODY$
+  BEGIN
+    REFRESH MATERIALIZED VIEW osm_transportation_name_linestring CONCURRENTLY;
+    REFRESH MATERIALIZED VIEW osm_transportation_name_linestring_gen1 CONCURRENTLY;
+    REFRESH MATERIALIZED VIEW osm_transportation_name_linestring_gen2 CONCURRENTLY;
+    REFRESH MATERIALIZED VIEW osm_transportation_name_linestring_gen3 CONCURRENTLY;
+      RETURN null;
+  END;
+  $BODY$
+language plpgsql
+
+CREATE TRIGGER trigger_refresh_osm_transportation_name_linestring
+    AFTER INSERT OR UPDATE OR DELETE ON osm_highway_linestring
+    FOR EACH STATEMENT
+    EXECUTE PROCEDURE refresh_osm_transportation_name_linestring
+
+
+
+
+
+
diff --git a/layers/water_name/water_lakeline.sql b/layers/water_name/water_lakeline.sql
index 16522e8..7110a09 100644
--- a/layers/water_name/water_lakeline.sql
+++ b/layers/water_name/water_lakeline.sql
@@ -1,9 +1,7 @@
 
-DROP TABLE IF EXISTS osm_water_lakeline CASCADE;
-
 -- etldoc:  osm_water_polygon ->  osm_water_lakeline
 -- etldoc:  lake_centerline  ->  osm_water_lakeline
-CREATE TABLE IF NOT EXISTS osm_water_lakeline AS (
+CREATE MATERIALIZED VIEW osm_water_lakeline AS (
 	SELECT wp.osm_id,
 		ll.wkb_geometry AS geometry,
 		name, name_en, ST_Area(wp.geometry) AS area
@@ -11,5 +9,20 @@ CREATE TABLE IF NOT EXISTS osm_water_lakeline AS (
     INNER JOIN lake_centerline ll ON wp.osm_id = ll.osm_id
     WHERE wp.name <> ''
 );
-
 CREATE INDEX IF NOT EXISTS osm_water_lakeline_geometry_idx ON osm_water_lakeline USING gist(geometry);
+
+-- Triggers
+
+CREATE OR REPLACE FUNCTION refresh_osm_water_lakeline() RETURNS trigger AS
+  $BODY$
+  BEGIN
+    REFRESH MATERIALIZED VIEW osm_water_lakeline CONCURRENTLY;
+      RETURN null;
+  END;
+  $BODY$
+language plpgsql
+
+CREATE TRIGGER trigger_refresh_osm_water_lakeline
+    AFTER INSERT OR UPDATE OR DELETE ON osm_water_polygon
+    FOR EACH STATEMENT
+    EXECUTE PROCEDURE refresh_osm_water_lakeline
diff --git a/layers/water_name/water_point.sql b/layers/water_name/water_point.sql
index 498a6e8..495aeab 100644
--- a/layers/water_name/water_point.sql
+++ b/layers/water_name/water_point.sql
@@ -1,9 +1,7 @@
 
-DROP TABLE IF EXISTS osm_water_point CASCADE;
-
 -- etldoc:  osm_water_polygon ->  osm_water_point
 -- etldoc:  lake_centerline ->  osm_water_point
-CREATE TABLE IF NOT EXISTS osm_water_point AS (
+CREATE MATERIALIZED VIEW osm_water_point AS (
     SELECT
         wp.osm_id, topoint(wp.geometry) AS geometry,
         wp.name, wp.name_en, ST_Area(wp.geometry) AS area
@@ -11,5 +9,20 @@ CREATE TABLE IF NOT EXISTS osm_water_point AS (
     LEFT JOIN lake_centerline ll ON wp.osm_id = ll.osm_id
     WHERE ll.osm_id IS NULL AND wp.name <> ''
 );
-
 CREATE INDEX IF NOT EXISTS osm_water_point_geometry_idx ON osm_water_point USING gist (geometry);
+
+-- Triggers
+
+CREATE OR REPLACE FUNCTION refresh_osm_water_point() RETURNS trigger AS
+  $BODY$
+  BEGIN
+    REFRESH MATERIALIZED VIEW osm_water_point CONCURRENTLY;
+      RETURN null;
+  END;
+  $BODY$
+language plpgsql
+
+CREATE TRIGGER trigger_refresh_osm_water_point
+    AFTER INSERT OR UPDATE OR DELETE ON osm_water_polygon
+    FOR EACH STATEMENT
+    EXECUTE PROCEDURE refresh_osm_water_point
diff --git a/layers/waterway/merge_waterway.sql b/layers/waterway/merge_waterway.sql
index 604e004..2d75f2c 100644
--- a/layers/waterway/merge_waterway.sql
+++ b/layers/waterway/merge_waterway.sql
@@ -1,15 +1,10 @@
 
-DROP TABLE IF EXISTS osm_important_waterway_linestring CASCADE;
-DROP TABLE IF EXISTS osm_important_waterway_linestring_gen1 CASCADE;
-DROP TABLE IF EXISTS osm_important_waterway_linestring_gen2 CASCADE;
-DROP TABLE IF EXISTS osm_important_waterway_linestring_gen3 CASCADE;
-
 -- 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
-CREATE TABLE IF NOT EXISTS osm_important_waterway_linestring AS (
+CREATE MATERIALIZED VIEW osm_important_waterway_linestring AS (
     SELECT
         (ST_Dump(geometry)).geom AS geometry,
         name
@@ -22,11 +17,10 @@ CREATE TABLE IF NOT EXISTS osm_important_waterway_linestring AS (
         GROUP BY name
     ) 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 TABLE IF NOT EXISTS osm_important_waterway_linestring_gen1 AS (
+CREATE MATERIALIZED VIEW osm_important_waterway_linestring_gen1 AS (
     SELECT ST_Simplify(geometry, 60) AS geometry, name
     FROM osm_important_waterway_linestring
     WHERE ST_Length(geometry) > 1000
@@ -34,7 +28,7 @@ CREATE TABLE IF NOT EXISTS osm_important_waterway_linestring_gen1 AS (
 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 TABLE IF NOT EXISTS osm_important_waterway_linestring_gen2 AS (
+CREATE MATERIALIZED VIEW osm_important_waterway_linestring_gen2 AS (
     SELECT ST_Simplify(geometry, 100) AS geometry, name
     FROM osm_important_waterway_linestring_gen1
     WHERE ST_Length(geometry) > 4000
@@ -42,9 +36,32 @@ CREATE TABLE IF NOT EXISTS osm_important_waterway_linestring_gen2 AS (
 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 TABLE IF NOT EXISTS osm_important_waterway_linestring_gen3 AS (
+CREATE MATERIALIZED VIEW osm_important_waterway_linestring_gen3 AS (
     SELECT ST_Simplify(geometry, 200) AS geometry, name
     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);
+
+--- Triggers
+
+CREATE OR REPLACE FUNCTION refresh_osm_important_waterway_linestring() RETURNS trigger AS
+  $BODY$
+  BEGIN
+    REFRESH MATERIALIZED VIEW osm_important_waterway_linestring CONCURRENTLY;
+    REFRESH MATERIALIZED VIEW osm_important_waterway_linestring_gen1 CONCURRENTLY;
+    REFRESH MATERIALIZED VIEW osm_important_waterway_linestring_gen2 CONCURRENTLY;
+    REFRESH MATERIALIZED VIEW osm_important_waterway_linestring_gen3 CONCURRENTLY;
+      RETURN null;
+  END;
+  $BODY$
+language plpgsql
+
+CREATE TRIGGER trigger_refresh_osm_important_waterway_linestring
+    AFTER INSERT OR UPDATE OR DELETE ON osm_waterway_linestring
+    FOR EACH STATEMENT
+    EXECUTE PROCEDURE refresh_osm_important_waterway_linestring
+
+
+
+