From 35a5ba1ade61ec53aed66771065dd80c774b9b9b Mon Sep 17 00:00:00 2001
From: stirringhalo <stirringhalo@users.noreply.github.com>
Date: Wed, 4 Jan 2017 15:53:58 -0500
Subject: [PATCH] Lakelines refresh once at commit time.

---
 layers/water_name/water_lakeline.sql | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/layers/water_name/water_lakeline.sql b/layers/water_name/water_lakeline.sql
index 0d66c69..d122371 100644
--- a/layers/water_name/water_lakeline.sql
+++ b/layers/water_name/water_lakeline.sql
@@ -11,14 +11,23 @@ CREATE MATERIALIZED VIEW osm_water_lakeline AS (
 ) WITH NO DATA;
 CREATE INDEX IF NOT EXISTS osm_water_lakeline_geometry_idx ON osm_water_lakeline USING gist(geometry);
 
--- Triggers
+-- Handle updates
+
+CREATE TABLE IF NOT EXISTS updates_osm_water_polygon(id serial primary key, t text, unique (t));
+CREATE OR REPLACE FUNCTION flag_update_osm_water_polygon() RETURNS trigger AS $$
+BEGIN
+    INSERT INTO updates_osm_water_polygon(t) VALUES ('y')  ON CONFLICT(t) DO NOTHING;
+    RETURN null;
+END;    
+$$ language plpgsql;
 
 CREATE OR REPLACE FUNCTION refresh_osm_water_lakeline() RETURNS trigger AS
   $BODY$
   BEGIN
     RAISE LOG 'Refresh osm_water_lakeline based tables';
-    REFRESH MATERIALIZED VIEW CONCURRENTLY osm_water_lakeline;
-      RETURN null;
+    REFRESH MATERIALIZED VIEW osm_water_lakeline;
+    DELETE FROM updates_osm_water_polygon;
+    RETURN null;
   END;
   $BODY$
 language plpgsql;
@@ -26,4 +35,10 @@ language plpgsql;
 CREATE TRIGGER trigger_refresh_osm_water_lakeline
     AFTER INSERT OR UPDATE OR DELETE ON osm_water_polygon
     FOR EACH STATEMENT
+    EXECUTE PROCEDURE flag_update_osm_water_polygon();
+
+CREATE CONSTRAINT TRIGGER commit_osm_water_polygon 
+    AFTER INSERT ON updates_osm_water_polygon
+    INITIALLY DEFERRED
+    FOR EACH ROW
     EXECUTE PROCEDURE refresh_osm_water_lakeline();