diff --git a/layers/housenumber/housenumber_centroid.sql b/layers/housenumber/housenumber_centroid.sql
index 24c05ae..29c687e 100644
--- a/layers/housenumber/housenumber_centroid.sql
+++ b/layers/housenumber/housenumber_centroid.sql
@@ -1,3 +1,5 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_housenumber_point;
+DROP TRIGGER IF EXISTS trigger_refresh ON housenumber.updates;
 
 -- etldoc: osm_housenumber_point -> osm_housenumber_point
 CREATE OR REPLACE FUNCTION convert_housenumber_point() RETURNS VOID AS $$
@@ -24,16 +26,13 @@ CREATE OR REPLACE FUNCTION housenumber.refresh() RETURNS trigger AS
   $BODY$
   BEGIN
     RAISE LOG 'Refresh housenumber';
-    SELECT convert_housenumber_point();
+    PERFORM convert_housenumber_point();
     DELETE FROM housenumber.updates;
     RETURN null;
   END;
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_housenumber_point;
-DROP TRIGGER IF EXISTS trigger_refresh ON housenumber.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_housenumber_point
     FOR EACH STATEMENT
diff --git a/layers/place/island_polygon_update.sql b/layers/place/island_polygon_update.sql
index 04c5432..ef937a5 100644
--- a/layers/place/island_polygon_update.sql
+++ b/layers/place/island_polygon_update.sql
@@ -1,3 +1,6 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_island_polygon;
+DROP TRIGGER IF EXISTS trigger_refresh ON place_island.updates;
+
 -- etldoc:  osm_island_polygon ->  osm_island_polygon
 CREATE OR REPLACE FUNCTION convert_island_polygon_point() RETURNS VOID AS $$
 BEGIN
@@ -24,16 +27,13 @@ CREATE OR REPLACE FUNCTION place_island.refresh() RETURNS trigger AS
   $BODY$
   BEGIN
     RAISE LOG 'Refresh place_island';
-    SELECT convert_island_polygon_point();
+    PERFORM convert_island_polygon_point();
     DELETE FROM place_island.updates;
     RETURN null;
   END;
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_island_polygon;
-DROP TRIGGER IF EXISTS trigger_refresh ON place_island.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_island_polygon
     FOR EACH STATEMENT
diff --git a/layers/place/merge_city_rank.sql b/layers/place/merge_city_rank.sql
index e7d9276..fa91994 100644
--- a/layers/place/merge_city_rank.sql
+++ b/layers/place/merge_city_rank.sql
@@ -1,7 +1,8 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_city_point;
+DROP TRIGGER IF EXISTS trigger_refresh ON place_city.updates;
 
 CREATE EXTENSION IF NOT EXISTS unaccent;
 
-
 CREATE OR REPLACE FUNCTION update_osm_city_point() RETURNS VOID AS $$
 BEGIN
 
@@ -62,16 +63,13 @@ CREATE OR REPLACE FUNCTION place_city.refresh() RETURNS trigger AS
   $BODY$
   BEGIN
     RAISE LOG 'Refresh place_city rank';
-    SELECT update_osm_city_point();
+    PERFORM update_osm_city_point();
     DELETE FROM place_city.updates;
     RETURN null;
   END;
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_city_point;
-DROP TRIGGER IF EXISTS trigger_refresh ON place_city.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_city_point
     FOR EACH STATEMENT
diff --git a/layers/place/merge_country_rank.sql b/layers/place/merge_country_rank.sql
index fbf1d95..afc14ea 100644
--- a/layers/place/merge_country_rank.sql
+++ b/layers/place/merge_country_rank.sql
@@ -1,3 +1,6 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_country_point;
+DROP TRIGGER IF EXISTS trigger_refresh ON place_country.updates;
+
 ALTER TABLE osm_country_point DROP CONSTRAINT IF EXISTS osm_country_point_rank_constraint;
 
 -- etldoc: ne_10m_admin_0_countries   -> osm_country_point
@@ -57,16 +60,13 @@ CREATE OR REPLACE FUNCTION place_country.refresh() RETURNS trigger AS
   $BODY$
   BEGIN
     RAISE LOG 'Refresh place_country rank';
-    SELECT update_osm_country_point();
+    PERFORM update_osm_country_point();
     DELETE FROM place_country.updates;
     RETURN null;
   END;
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_country_point;
-DROP TRIGGER IF EXISTS trigger_refresh ON place_country.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_country_point
     FOR EACH STATEMENT
diff --git a/layers/place/merge_state_rank.sql b/layers/place/merge_state_rank.sql
index 90c9616..fcf3279 100644
--- a/layers/place/merge_state_rank.sql
+++ b/layers/place/merge_state_rank.sql
@@ -1,3 +1,6 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_state_point;
+DROP TRIGGER IF EXISTS trigger_refresh ON place_state.updates;
+
 ALTER TABLE osm_state_point DROP CONSTRAINT IF EXISTS osm_state_point_rank_constraint;
 
 -- etldoc: ne_10m_admin_1_states_provinces_shp   -> osm_state_point
@@ -53,16 +56,13 @@ CREATE OR REPLACE FUNCTION place_state.refresh() RETURNS trigger AS
   $BODY$
   BEGIN
     RAISE LOG 'Refresh place_state rank';
-    SELECT update_osm_state_point();
+    PERFORM update_osm_state_point();
     DELETE FROM place_state.updates;
     RETURN null;
   END;
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_state_point;
-DROP TRIGGER IF EXISTS trigger_refresh ON place_state.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_state_point
     FOR EACH STATEMENT
diff --git a/layers/poi/poi_polygon_update.sql b/layers/poi/poi_polygon_update.sql
index dcd4b3b..22484ac 100644
--- a/layers/poi/poi_polygon_update.sql
+++ b/layers/poi/poi_polygon_update.sql
@@ -1,3 +1,6 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_poi_polygon;
+DROP TRIGGER IF EXISTS trigger_refresh ON poi.updates;
+
 -- etldoc:  osm_poi_polygon ->  osm_poi_polygon
 
 CREATE OR REPLACE FUNCTION convert_poi_point() RETURNS VOID AS $$
@@ -25,16 +28,13 @@ CREATE OR REPLACE FUNCTION poi.refresh() RETURNS trigger AS
   $BODY$
   BEGIN
     RAISE LOG 'Refresh poi';
-    SELECT convert_poi_point();
+    PERFORM convert_poi_point();
     DELETE FROM poi.updates;
     RETURN null;
   END;
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_poi_polygon;
-DROP TRIGGER IF EXISTS trigger_refresh ON poi.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_poi_polygon
     FOR EACH STATEMENT
diff --git a/layers/transportation_name/merge_highways.sql b/layers/transportation_name/merge_highways.sql
index 0648acb..025b274 100644
--- a/layers/transportation_name/merge_highways.sql
+++ b/layers/transportation_name/merge_highways.sql
@@ -1,3 +1,5 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_highway_linestring;
+DROP TRIGGER IF EXISTS trigger_refresh ON transportation_name.updates;
 
 -- Instead of using relations to find out the road names we
 -- stitch together the touching ways with the same name
@@ -87,9 +89,6 @@ CREATE OR REPLACE FUNCTION transportation_name.refresh() RETURNS trigger AS
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_highway_linestring;
-DROP TRIGGER IF EXISTS trigger_refresh ON transportation_name.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_highway_linestring
     FOR EACH STATEMENT
diff --git a/layers/water_name/water_lakeline.sql b/layers/water_name/water_lakeline.sql
index b918f4b..3570cc2 100644
--- a/layers/water_name/water_lakeline.sql
+++ b/layers/water_name/water_lakeline.sql
@@ -1,3 +1,5 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_water_polygon;
+DROP TRIGGER IF EXISTS trigger_refresh ON water_lakeline.updates;
 
 -- etldoc:  osm_water_polygon ->  osm_water_lakeline
 -- etldoc:  lake_centerline  ->  osm_water_lakeline
@@ -36,9 +38,6 @@ CREATE OR REPLACE FUNCTION water_lakeline.refresh() RETURNS trigger AS
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_water_polygon;
-DROP TRIGGER IF EXISTS trigger_refresh ON water_lakeline.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_water_polygon
     FOR EACH STATEMENT
diff --git a/layers/water_name/water_point.sql b/layers/water_name/water_point.sql
index 2bf0de8..7c49547 100644
--- a/layers/water_name/water_point.sql
+++ b/layers/water_name/water_point.sql
@@ -1,3 +1,5 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_water_polygon;
+DROP TRIGGER IF EXISTS trigger_refresh ON water_name.updates;
 
 -- etldoc:  osm_water_polygon ->  osm_water_point
 -- etldoc:  lake_centerline ->  osm_water_point
@@ -36,9 +38,6 @@ CREATE OR REPLACE FUNCTION water_name.refresh() RETURNS trigger AS
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_water_polygon;
-DROP TRIGGER IF EXISTS trigger_refresh ON water_name.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_water_polygon
     FOR EACH STATEMENT
diff --git a/layers/waterway/merge_waterway.sql b/layers/waterway/merge_waterway.sql
index 614cfae..e3bcd89 100644
--- a/layers/waterway/merge_waterway.sql
+++ b/layers/waterway/merge_waterway.sql
@@ -1,3 +1,5 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_waterway_linestring;
+DROP TRIGGER IF EXISTS trigger_refresh ON waterway.updates;
 
 -- We merge the waterways by name like the highways
 -- This helps to drop not important rivers (since they do not have a name)
@@ -74,9 +76,6 @@ CREATE OR REPLACE FUNCTION waterway.refresh() RETURNS trigger AS
   $BODY$
 language plpgsql;
 
-DROP TRIGGER IF EXISTS trigger_flag ON osm_waterway_linestring;
-DROP TRIGGER IF EXISTS trigger_refresh ON waterway.updates;
-
 CREATE TRIGGER trigger_flag
     AFTER INSERT OR UPDATE OR DELETE ON osm_waterway_linestring
     FOR EACH STATEMENT