4a1b0afa26
Instead of using [Douglas-Peucker algorithm](https://postgis.net/docs/ST_SimplifyPreserveTopology.html) which is using for generalized tables [imposm](https://imposm.org/docs/imposm3/latest/mapping.html#generalized-tables) it is used [Visvalingam-Whyatt algorithm](https://postgis.net/docs/ST_SimplifyVW.html). Solution: remove imposm generalized tables (during `import-osm`) and create generalization in `import-sql` step for zooms 7-14. Zooms 0-6 are from Natural Earth data. Upper zoom levels (7 and 8) are ok to merge with no big impact on creation speed. In Canada from z9 it took too long. Between zoom levels 10 - 13 there can be union polygons with less than 300 edge points (empirical number based on a test on Canada forest, can be discussed). Polygons with more than 300 edge points are just simplified. Zoom 14 is from the original dataset `osm_landcover_polygon`. There is also removed `osm_id` which is never used and not passed into vector tiles.
277 lines
8.0 KiB
SQL
277 lines
8.0 KiB
SQL
DROP TABLE IF EXISTS osm_landcover_gen_z7;
|
|
DROP TABLE IF EXISTS osm_landcover_gen_z8;
|
|
DROP TABLE IF EXISTS osm_landcover_gen_z9;
|
|
DROP TABLE IF EXISTS osm_landcover_gen_z10;
|
|
DROP TABLE IF EXISTS osm_landcover_gen_z11;
|
|
DROP TABLE IF EXISTS osm_landcover_gen_z12;
|
|
DROP TABLE IF EXISTS osm_landcover_gen_z13;
|
|
|
|
-- etldoc: osm_landcover_polygon -> osm_landcover_gen_z7
|
|
CREATE TABLE osm_landcover_gen_z7 AS
|
|
(
|
|
WITH simplify_vw_z7 AS
|
|
(
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
ST_SimplifyVW(geometry, zres(7)*zres(7))) AS geometry
|
|
FROM osm_landcover_polygon
|
|
WHERE ST_Area(geometry) > power(zres(5),2)
|
|
)
|
|
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
(ST_Dump(
|
|
ST_Union(geometry))).geom) AS geometry
|
|
FROM
|
|
(
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) OVER () AS cid,
|
|
geometry
|
|
FROM simplify_vw_z7
|
|
) union_geom
|
|
GROUP BY subclass,
|
|
cid
|
|
);
|
|
|
|
CREATE INDEX ON osm_landcover_gen_z7 USING GIST (geometry);
|
|
|
|
-- etldoc: osm_landcover_polygon -> osm_landcover_gen_z8
|
|
CREATE TABLE osm_landcover_gen_z8 AS
|
|
(
|
|
WITH simplify_vw_z8 AS
|
|
(
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
ST_SimplifyVW(geometry, zres(8)*zres(8))) AS geometry
|
|
FROM osm_landcover_polygon
|
|
WHERE ST_Area(geometry) > power(zres(6),2)
|
|
)
|
|
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
(ST_Dump(
|
|
ST_Union(geometry))).geom) AS geometry
|
|
FROM
|
|
(
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) OVER () AS cid,
|
|
geometry
|
|
FROM simplify_vw_z8
|
|
) union_geom
|
|
GROUP BY subclass,
|
|
cid
|
|
);
|
|
|
|
CREATE INDEX ON osm_landcover_gen_z8 USING GIST (geometry);
|
|
|
|
-- etldoc: osm_landcover_polygon -> osm_landcover_gen_z9
|
|
CREATE TABLE osm_landcover_gen_z9 AS
|
|
(
|
|
WITH simplify_vw_z9 AS
|
|
(
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
ST_SimplifyVW(geometry, zres(9)*zres(9))) AS geometry
|
|
FROM osm_landcover_polygon
|
|
WHERE ST_Area(geometry) > power(zres(7),2)
|
|
)
|
|
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
(ST_dump(
|
|
ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z9
|
|
WHERE ST_NPoints(geometry) < 50) union_geom50
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass, st_makevalid((ST_dump(ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z9
|
|
WHERE ST_NPoints(geometry) >= 50 AND ST_NPoints(geometry) < 300) union_geom300
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
(ST_Dump(
|
|
ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z9
|
|
WHERE ST_NPoints(geometry) >= 300) union_geom_rest
|
|
GROUP BY subclass,
|
|
cid
|
|
);
|
|
|
|
CREATE INDEX ON osm_landcover_gen_z9 USING GIST (geometry);
|
|
|
|
-- etldoc: osm_landcover_polygon -> osm_landcover_gen_z10
|
|
CREATE TABLE osm_landcover_gen_z10 AS
|
|
(
|
|
WITH simplify_vw_z10 AS
|
|
(
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
ST_SimplifyVW(geometry, zres(10)*zres(10))) AS geometry
|
|
FROM osm_landcover_polygon
|
|
WHERE ST_Area(geometry) > power(zres(8),2)
|
|
)
|
|
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
(ST_dump(
|
|
ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z10
|
|
WHERE ST_NPoints(geometry) < 50) union_geom50
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass, st_makevalid((ST_dump(ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z10
|
|
WHERE ST_NPoints(geometry) >= 50 AND ST_NPoints(geometry) < 300) union_geom300
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass,
|
|
geometry
|
|
FROM simplify_vw_z10
|
|
WHERE ST_NPoints(geometry) >= 300
|
|
);
|
|
|
|
CREATE INDEX ON osm_landcover_gen_z10 USING GIST (geometry);
|
|
|
|
-- etldoc: osm_landcover_polygon -> osm_landcover_gen_z11
|
|
CREATE TABLE osm_landcover_gen_z11 AS
|
|
(
|
|
WITH simplify_vw_z11 AS
|
|
(
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
ST_SimplifyVW(geometry, zres(11)*zres(11))) AS geometry
|
|
FROM osm_landcover_polygon
|
|
WHERE ST_Area(geometry) > power(zres(8),2)
|
|
)
|
|
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
(ST_dump(
|
|
ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z11
|
|
WHERE ST_NPoints(geometry) < 50) union_geom50
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass, st_makevalid((ST_dump(ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z11
|
|
WHERE ST_NPoints(geometry) >= 50 AND ST_NPoints(geometry) < 300) union_geom300
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass,
|
|
geometry
|
|
FROM simplify_vw_z11
|
|
WHERE ST_NPoints(geometry) >= 300
|
|
);
|
|
|
|
CREATE INDEX ON osm_landcover_gen_z11 USING GIST (geometry);
|
|
|
|
-- etldoc: osm_landcover_polygon -> osm_landcover_gen_z12
|
|
CREATE TABLE osm_landcover_gen_z12 AS
|
|
(
|
|
WITH simplify_vw_z12 AS
|
|
(
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
ST_SimplifyVW(geometry, zres(12)*zres(12))) AS geometry
|
|
FROM osm_landcover_polygon
|
|
WHERE ST_Area(geometry) > power(zres(9),2)
|
|
)
|
|
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
(ST_dump(
|
|
ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z12
|
|
WHERE ST_NPoints(geometry) < 50) union_geom50
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass, st_makevalid((ST_dump(ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z12
|
|
WHERE ST_NPoints(geometry) >= 50 AND ST_NPoints(geometry) < 300) union_geom300
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass,
|
|
geometry
|
|
FROM simplify_vw_z12
|
|
WHERE ST_NPoints(geometry) >= 300
|
|
);
|
|
|
|
CREATE INDEX ON osm_landcover_gen_z12 USING GIST (geometry);
|
|
|
|
-- etldoc: osm_landcover_polygon -> osm_landcover_gen_z13
|
|
CREATE TABLE osm_landcover_gen_z13 AS
|
|
(
|
|
WITH simplify_vw_z13 AS
|
|
(
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
ST_SimplifyVW(geometry, zres(13)*zres(13))) AS geometry
|
|
FROM osm_landcover_polygon
|
|
WHERE ST_Area(geometry) > power(zres(10),2)
|
|
)
|
|
|
|
SELECT subclass,
|
|
ST_MakeValid(
|
|
(ST_dump(
|
|
ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z13
|
|
WHERE ST_NPoints(geometry) < 50) union_geom50
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass, st_makevalid((ST_dump(ST_Union(geometry))).geom) AS geometry
|
|
FROM (
|
|
SELECT subclass,
|
|
ST_ClusterDBSCAN(geometry, eps := 0, minpoints := 1) over () AS cid, geometry
|
|
FROM simplify_vw_z13
|
|
WHERE ST_NPoints(geometry) >= 50 AND ST_NPoints(geometry) < 300) union_geom300
|
|
GROUP BY subclass,
|
|
cid
|
|
UNION ALL
|
|
SELECT subclass,
|
|
geometry
|
|
FROM simplify_vw_z13
|
|
WHERE ST_NPoints(geometry) >= 300
|
|
);
|
|
|
|
CREATE INDEX ON osm_landcover_gen_z13 USING GIST (geometry); |