added bootstrap buildings

db/init/01_postgis.sql

@@ -1 +1,2 @@
 CREATE EXTENSION IF NOT EXISTS postgis;
+CREATE EXTENSION IF NOT EXISTS hstore;

db/sql/normalize_buildings.sql

@@ -0,0 +1,56 @@
+DROP TABLE IF EXISTS buildings CASCADE;
+
+CREATE TABLE buildings AS
+WITH raw AS (
+  SELECT
+    osm_id,
+    way,
+    NULLIF(building, '') AS building_type,
+    substring(replace(COALESCE(tags -> 'height', ''), ',', '.') FROM '[-+]?[0-9]+(\.[0-9]+)?')::real
+      AS height_value,
+    substring(replace(COALESCE(tags -> 'building:levels', ''), ',', '.') FROM '[-+]?[0-9]+(\.[0-9]+)?')::real
+      AS levels_value
+  FROM planet_osm_polygon
+  WHERE building IS NOT NULL
+    AND building <> ''
+    AND building <> 'no'
+),
+normalized AS (
+  SELECT
+    osm_id,
+    ST_Multi(ST_CollectionExtract(ST_MakeValid(way), 3)) AS geom,
+    building_type,
+    height_value,
+    levels_value
+  FROM raw
+)
+SELECT
+  osm_id,
+  geom,
+  CASE
+    WHEN height_value IS NOT NULL AND height_value > 0 THEN height_value
+    WHEN levels_value IS NOT NULL AND levels_value > 0 THEN levels_value * 3.0
+    WHEN building_type IN ('garage', 'garages', 'shed') THEN 3.0
+    WHEN building_type IN ('industrial', 'warehouse') THEN 8.0
+    WHEN building_type IN ('church', 'cathedral') THEN 12.0
+    ELSE 9.0
+  END::real AS height_m,
+  CASE
+    WHEN levels_value IS NOT NULL AND levels_value > 0 THEN levels_value::integer
+    ELSE NULL
+  END AS levels,
+  building_type,
+  CASE
+    WHEN height_value IS NOT NULL AND height_value > 0 THEN 'measured'
+    ELSE 'estimated'
+  END AS source
+FROM normalized
+WHERE NOT ST_IsEmpty(geom);
+
+ALTER TABLE buildings ALTER COLUMN geom TYPE geometry(MultiPolygon, 4326)
+  USING ST_SetSRID(geom, 4326);
+
+CREATE INDEX IF NOT EXISTS buildings_geom_gix ON buildings USING GIST (geom);
+CREATE INDEX IF NOT EXISTS buildings_height_idx ON buildings (height_m);
+CREATE INDEX IF NOT EXISTS buildings_type_idx ON buildings (building_type);
+ANALYZE buildings;