maptiles/layers/transportation/update_transportation_merge.sql

DROP TRIGGER IF EXISTS trigger_store_osm_transportation_merge_linestring_gen_z8 ON osm_transportation_merge_linestring_gen_z8;
DROP TRIGGER IF EXISTS trigger_store_transportation_highway_linestring_gen_z9 ON osm_transportation_merge_linestring_gen_z9;
DROP TRIGGER IF EXISTS trigger_flag_transportation_z9 ON osm_transportation_merge_linestring_gen_z9;
DROP TRIGGER IF EXISTS trigger_refresh_z8 ON transportation.updates_z9;
DROP TRIGGER IF EXISTS trigger_store_transportation_highway_linestring_gen_z11 ON osm_highway_linestring_gen_z11;
DROP TRIGGER IF EXISTS trigger_store_osm_transportation_merge_linestring_gen_z11 ON osm_transportation_merge_linestring_gen_z11;
DROP TRIGGER IF EXISTS trigger_flag_transportation_z11 ON osm_highway_linestring_gen_z11;
DROP TRIGGER IF EXISTS trigger_refresh_z11 ON transportation.updates_z11;
DROP TRIGGER IF EXISTS trigger_store_transportation_name_network ON osm_transportation_name_network;

-- Determine whether a segment is long enough to have bridge/tunnel attributes
-- Dropping small brunnel sections allow for generalization as distinct segments get too small
CREATE OR REPLACE FUNCTION visible_brunnel(g geometry, brunnel boolean, zoom_level integer)
    RETURNS boolean AS
$$
SELECT
    brunnel AND
    -- Width of a tile in meters (111,842 is the length of one degree of latitude at the equator in meters)
    -- 111,842 * 180 / 2^zoom_level
    --  = 20131560 / POW(2, zoom_level)
    -- Drop brunnel if length of way < 2% of tile width (less than 3 pixels)
    ST_Length(g) *
        COS(RADIANS(ST_Y(ST_Centroid(ST_Transform(g, 4326))))) *
        POW(2, zoom_level) / 20131560 > 0.02
$$ LANGUAGE SQL IMMUTABLE
                PARALLEL SAFE;

-- Determine whether a segment is long enough to have layer attributes
CREATE OR REPLACE FUNCTION visible_layer(g geometry, layer int, zoom_level integer)
    RETURNS int AS
$$
SELECT
    CASE WHEN
    -- Width of a tile in meters (111,842 is the length of one degree of latitude at the equator in meters)
    -- 111,842 * 180 / 2^zoom_level
    --  = 20131560 / POW(2, zoom_level)
    -- Drop brunnel if length of way < 2% of tile width (less than 3 pixels)
    ST_Length(g) *
        COS(RADIANS(ST_Y(ST_Centroid(ST_Transform(g, 4326))))) *
        POW(2, zoom_level) / 20131560 > 0.02
    THEN layer END
$$ LANGUAGE SQL IMMUTABLE
                PARALLEL SAFE;

-- Determine whether a segment is long enough to have an attribute
CREATE OR REPLACE FUNCTION visible_text(g geometry, attr text, zoom_level integer)
    RETURNS text AS
$$
SELECT
    CASE WHEN
    -- Width of a tile in meters (111,842 is the length of one degree of latitude at the equator in meters)
    -- 111,842 * 180 / 2^zoom_level
    --  = 20131560 / POW(2, zoom_level)
    -- Drop brunnel if length of way < 2% of tile width (less than 3 pixels)
    ST_Length(g) *
        COS(RADIANS(ST_Y(ST_Centroid(ST_Transform(g, 4326))))) *
        POW(2, zoom_level) / 20131560 > 0.02
    THEN attr END
$$ LANGUAGE SQL IMMUTABLE
                PARALLEL SAFE;

-- 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_network
-- etldoc: transportation_route_member_coalesced ->  osm_transportation_name_network
DROP TABLE IF EXISTS osm_transportation_name_network;
CREATE TABLE osm_transportation_name_network AS
SELECT
    geometry,
    osm_id,
    tags || get_basic_names(tags, geometry) AS tags,
    ref,
    highway,
    subclass,
    brunnel,
    "level",
    sac_scale,
    layer,
    indoor,
    network_type,
    route_1, route_2, route_3, route_4, route_5, route_6,
    z_order,
    route_rank
FROM (
    SELECT DISTINCT ON (hl.osm_id)
        hl.geometry,
        hl.osm_id,
        transportation_name_tags(hl.geometry, hl.tags, hl.name, hl.name_en, hl.name_de) AS tags,
        rm1.network_type,
        CASE
            WHEN rm1.network_type IS NOT NULL AND rm1.ref::text <> ''
                THEN rm1.ref::text
            ELSE NULLIF(hl.ref, '')
            END AS ref,
        hl.highway,
        NULLIF(hl.construction, '') AS subclass,
        brunnel(hl.is_bridge, hl.is_tunnel, hl.is_ford) AS brunnel,
        sac_scale,
        CASE WHEN highway IN ('footway', 'steps') THEN layer END AS layer,
        CASE WHEN highway IN ('footway', 'steps') THEN level END AS level,
        CASE WHEN highway IN ('footway', 'steps') THEN indoor END AS indoor,
        create_route_hstore(rm1.network, rm1.ref, rm1.name, rm1.colour, rm1.ref_colour) AS route_1,
        create_route_hstore(rm2.network, rm2.ref, rm2.name, rm2.colour, rm2.ref_colour) AS route_2,
        create_route_hstore(rm3.network, rm3.ref, rm3.name, rm3.colour, rm3.ref_colour) AS route_3,
        create_route_hstore(rm4.network, rm4.ref, rm4.name, rm4.colour, rm4.ref_colour) AS route_4,
        create_route_hstore(rm5.network, rm5.ref, rm5.name, rm5.colour, rm5.ref_colour) AS route_5,
        create_route_hstore(rm6.network, rm6.ref, rm6.name, rm6.colour, rm6.ref_colour) AS route_6,
        hl.z_order,
        LEAST(rm1.rank, rm2.rank, rm3.rank, rm4.rank, rm5.rank, rm6.rank) AS route_rank
    FROM osm_highway_linestring hl
            LEFT OUTER JOIN transportation_route_member_coalesced rm1 ON rm1.member = hl.osm_id AND rm1.concurrency_index=1
            LEFT OUTER JOIN transportation_route_member_coalesced rm2 ON rm2.member = hl.osm_id AND rm2.concurrency_index=2
            LEFT OUTER JOIN transportation_route_member_coalesced rm3 ON rm3.member = hl.osm_id AND rm3.concurrency_index=3
            LEFT OUTER JOIN transportation_route_member_coalesced rm4 ON rm4.member = hl.osm_id AND rm4.concurrency_index=4
            LEFT OUTER JOIN transportation_route_member_coalesced rm5 ON rm5.member = hl.osm_id AND rm5.concurrency_index=5
            LEFT OUTER JOIN transportation_route_member_coalesced rm6 ON rm6.member = hl.osm_id AND rm6.concurrency_index=6
    WHERE (hl.name <> '' OR hl.ref <> '' OR rm1.ref <> '' OR rm1.network <> '')
      AND hl.highway <> ''
) AS t;

-- Create Primary-Key for osm_transportation_name_network table
DO $$
BEGIN
    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_name_network' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_name_network ADD PRIMARY KEY (osm_id);
    END IF;
END;
$$ LANGUAGE plpgsql;

-- Geometry Index
CREATE INDEX IF NOT EXISTS osm_transportation_name_network_geometry_idx
    ON osm_transportation_name_network USING gist (geometry);

-- etldoc: osm_highway_linestring_gen_z11 ->  osm_transportation_merge_linestring_gen_z11
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z11(
    geometry geometry('LineString'),
    id SERIAL,
    osm_id bigint,
    source_ids bigint[],
    highway character varying,
    network character varying,
    construction character varying,
    is_bridge boolean,
    is_tunnel boolean,
    is_ford boolean,
    expressway boolean,
    z_order integer,
    bicycle character varying,
    foot character varying,
    horse character varying,
    mtb_scale character varying,
    sac_scale character varying,
    access text,
    toll boolean,
    layer integer
);

ALTER TABLE osm_transportation_merge_linestring_gen_z11 ADD COLUMN IF NOT EXISTS source_ids bigint[];

-- Create osm_transportation_merge_linestring_gen_z10 as a copy of osm_transportation_merge_linestring_gen_z11 but
-- drop the "source_ids" column. This can be done because z10 and z9 tables are only simplified and not merged,
-- therefore relations to sources are direct via the id column.
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z10
    (LIKE osm_transportation_merge_linestring_gen_z11);
ALTER TABLE osm_transportation_merge_linestring_gen_z10 DROP COLUMN IF EXISTS source_ids;

-- Create osm_transportation_merge_linestring_gen_z9 as a copy of osm_transportation_merge_linestring_gen_z10
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z9
    (LIKE osm_transportation_merge_linestring_gen_z10);

-- Create OneToMany-Relation-Table storing relations of a Merged-LineString in table
-- osm_transportation_merge_linestring_gen_z11 to Source-LineStrings from table osm_highway_linestring_gen_z11
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z11_source_ids(
    id int,
    source_id bigint,
    PRIMARY KEY (id, source_id)
);

-- Index for storing OSM-IDs of Source-LineStrings
CREATE UNIQUE INDEX IF NOT EXISTS osm_highway_linestring_gen_z11_osm_id_idx ON osm_highway_linestring_gen_z11 ("osm_id");

-- Analyze created indexes
ANALYZE osm_highway_linestring_gen_z11;

-- Ensure tables are emtpy if they haven't been created
TRUNCATE osm_transportation_merge_linestring_gen_z11;
TRUNCATE osm_transportation_merge_linestring_gen_z11_source_ids;

-- Merge LineStrings from osm_highway_linestring_gen_z11 by grouping them and creating intersecting clusters of
-- each group via ST_ClusterDBSCAN
INSERT INTO osm_transportation_merge_linestring_gen_z11 (geometry, source_ids, highway, network, construction,
                                                         is_bridge, is_tunnel, is_ford, expressway, z_order,
                                                         bicycle, foot, horse, mtb_scale, sac_scale, access, toll,
                                                         layer)
SELECT (ST_Dump(ST_LineMerge(ST_Union(geometry)))).geom AS geometry,
       -- We use St_Union instead of St_Collect to ensure no overlapping points exist within the geometries to
       -- merge. https://postgis.net/docs/ST_Union.html
       -- ST_LineMerge only merges across singular intersections and groups its output into a MultiLineString if
       -- more than two LineStrings form an intersection or no intersection could be found.
       -- https://postgis.net/docs/ST_LineMerge.html
       -- In order to not end up with a mixture of LineStrings and MultiLineStrings we dump eventual
       -- MultiLineStrings via ST_Dump. https://postgis.net/docs/ST_Dump.html
       array_agg(osm_id) as source_ids,
       -- Temporary Merged-LineString to Source-LineStrings-ID column to store relations before they have been
       -- intersected
       highway,
       network,
       construction,
       is_bridge,
       is_tunnel,
       is_ford,
       expressway,
       min(z_order) as z_order,
       bicycle,
       foot,
       horse,
       mtb_scale,
       sac_scale,
       CASE
           WHEN access IN ('private', 'no') THEN 'no'
           ELSE NULL::text END AS access,
       toll,
       layer
FROM (
    SELECT osm_highway_linestring_normalized_brunnel_z11.*,
           -- Get intersecting clusters by setting minimum distance to 0 and minimum intersecting points to 1
           -- https://postgis.net/docs/ST_ClusterDBSCAN.html
           ST_ClusterDBSCAN(geometry, 0, 1) OVER (
               PARTITION BY highway, network, construction, is_bridge, is_tunnel, is_ford, expressway, bicycle,
                            foot, horse, mtb_scale, sac_scale, access, toll, layer
           ) AS cluster,
           -- ST_ClusterDBSCAN returns an increasing integer as the cluster-ids within each partition starting at 0.
           -- This leads to clusters having the same ID across multiple partitions therefore we generate a
           -- Cluster-Group-ID by utilizing the DENSE_RANK function sorted over the partition columns.
           DENSE_RANK() OVER (
               ORDER BY highway, network, construction, is_bridge, is_tunnel, is_ford, expressway, bicycle,
                        foot, horse, mtb_scale, sac_scale, access, toll, layer
           ) as cluster_group
    FROM (
        -- Remove bridge/tunnel/ford attributes from short sections of road so they can be merged
        SELECT geometry,
               osm_id,
               highway,
               network,
               construction,
               visible_brunnel(geometry, is_bridge, 11) AS is_bridge,
               visible_brunnel(geometry, is_tunnel, 11) AS is_tunnel,
               visible_brunnel(geometry, is_ford, 11) AS is_ford,
               expressway,
               z_order,
               bicycle,
               foot,
               horse,
               mtb_scale,
               sac_scale,
               access,
               toll,
               visible_layer(geometry, layer, 11) AS layer
        FROM osm_highway_linestring_gen_z11
    ) osm_highway_linestring_normalized_brunnel_z11
) q
GROUP BY cluster_group, cluster, highway, network, construction, is_bridge, is_tunnel, is_ford, expressway,
         bicycle, foot, horse, mtb_scale, sac_scale, access, toll, layer;

-- Geometry Index
CREATE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z11_geometry_idx
    ON osm_transportation_merge_linestring_gen_z11 USING gist (geometry);

-- Create Primary-Keys for osm_transportation_merge_linestring_gen_z11/z10/z9 tables
DO $$
BEGIN
    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_merge_linestring_gen_z11' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_merge_linestring_gen_z11 ADD PRIMARY KEY (id);
    END IF;

    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_merge_linestring_gen_z10' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_merge_linestring_gen_z10 ADD PRIMARY KEY (id);
    END IF;

    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_merge_linestring_gen_z9' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_merge_linestring_gen_z9 ADD PRIMARY KEY (id);
    END IF;
END;
$$ LANGUAGE plpgsql;

-- Indexes which can be utilized during full-update for queries originating from
-- insert_transportation_merge_linestring_gen_z10() function
CREATE UNIQUE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z11_update_partial_idx
    ON osm_transportation_merge_linestring_gen_z11 (id)
    WHERE highway NOT IN ('tertiary', 'tertiary_link', 'busway') AND
          construction NOT IN ('tertiary', 'tertiary_link', 'busway');

-- Analyze populated table with new indexes
ANALYZE osm_transportation_merge_linestring_gen_z11;

-- Store OSM-IDs of Source-LineStrings by intersecting Merged-LineStrings with their sources. This required because
-- ST_LineMerge only merges across singular intersections and groups its output into a MultiLineString if
-- more than two LineStrings form an intersection or no intersection could be found.
-- Execute after indexes have been created on osm_highway_linestring_gen_z11 to improve performance
INSERT INTO osm_transportation_merge_linestring_gen_z11_source_ids (id, source_id)
SELECT m.id, m.source_id
FROM (
    SELECT id, unnest(source_ids) AS source_id, geometry
    FROM osm_transportation_merge_linestring_gen_z11
) m
JOIN osm_highway_linestring_gen_z11 s ON (m.source_id = s.osm_id)
WHERE ST_Intersects(s.geometry, m.geometry)
ON CONFLICT (id, source_id) DO NOTHING;

-- Drop temporary Merged-LineString to Source-LineStrings-ID column
ALTER TABLE osm_transportation_merge_linestring_gen_z11 DROP COLUMN IF EXISTS source_ids;

CREATE SCHEMA IF NOT EXISTS transportation;

CREATE TABLE IF NOT EXISTS transportation.changes_z9_z10
(
    is_old boolean,
    id int,
    PRIMARY KEY (is_old, id)
);

CREATE OR REPLACE FUNCTION insert_transportation_merge_linestring_gen_z10(full_update bool) RETURNS void AS
$$
DECLARE
    t TIMESTAMP WITH TIME ZONE := clock_timestamp();
BEGIN
    RAISE LOG 'Refresh transportation z9 10';

    -- Analyze tracking and source tables before performing update
    ANALYZE transportation.changes_z9_z10;
    ANALYZE osm_transportation_merge_linestring_gen_z11;

    -- Remove entries which have been deleted from source table
    DELETE FROM osm_transportation_merge_linestring_gen_z10
    USING transportation.changes_z9_z10
    WHERE full_update IS TRUE OR (
        transportation.changes_z9_z10.is_old IS TRUE AND
        transportation.changes_z9_z10.id = osm_transportation_merge_linestring_gen_z10.id
    );

    -- etldoc: osm_transportation_merge_linestring_gen_z11 -> osm_transportation_merge_linestring_gen_z10
    INSERT INTO osm_transportation_merge_linestring_gen_z10
    SELECT ST_Simplify(geometry, ZRes(12)) AS geometry,
        id,
        osm_id,
        highway,
        network,
        construction,
        -- Remove bridge/tunnel/ford attributes from short sections of road so they can be merged
        visible_brunnel(geometry, is_bridge, 11) AS is_bridge,
        visible_brunnel(geometry, is_tunnel, 11) AS is_tunnel,
        visible_brunnel(geometry, is_ford, 11) AS is_ford,
        expressway,
        z_order,
        bicycle,
        foot,
        horse,
        mtb_scale,
        sac_scale,
        access,
        toll,
        visible_layer(geometry, layer, 11) AS layer
    FROM osm_transportation_merge_linestring_gen_z11
    WHERE (full_update IS TRUE OR EXISTS(
            SELECT NULL FROM transportation.changes_z9_z10
            WHERE transportation.changes_z9_z10.is_old IS FALSE AND
                  transportation.changes_z9_z10.id = osm_transportation_merge_linestring_gen_z11.id
        ))
        AND (
            highway NOT IN ('tertiary', 'tertiary_link', 'busway', 'bus_guideway')
            AND construction NOT IN ('tertiary', 'tertiary_link', 'busway', 'bus_guideway')
        )
    ON CONFLICT (id) DO UPDATE SET osm_id = excluded.osm_id, highway = excluded.highway, network = excluded.network,
                                   construction = excluded.construction, is_bridge = excluded.is_bridge,
                                   is_tunnel = excluded.is_tunnel, is_ford = excluded.is_ford,
                                   expressway = excluded.expressway, z_order = excluded.z_order,
                                   bicycle = excluded.bicycle, foot = excluded.foot, horse = excluded.horse,
                                   mtb_scale = excluded.mtb_scale, sac_scale = excluded.sac_scale,
                                   access = excluded.access, toll = excluded.toll, layer = excluded.layer;

    -- Remove entries which have been deleted from source table
    DELETE FROM osm_transportation_merge_linestring_gen_z9
    USING transportation.changes_z9_z10
    WHERE full_update IS TRUE OR (
        transportation.changes_z9_z10.is_old IS TRUE AND
        transportation.changes_z9_z10.id = osm_transportation_merge_linestring_gen_z9.id
    );

    -- Analyze source table
    ANALYZE osm_transportation_merge_linestring_gen_z10;

    -- etldoc: osm_transportation_merge_linestring_gen_z10 -> osm_transportation_merge_linestring_gen_z9
    INSERT INTO osm_transportation_merge_linestring_gen_z9
    SELECT ST_Simplify(geometry, ZRes(11)) AS geometry,
        id,
        osm_id,
        highway,
        network,
        construction,
        -- Remove bridge/tunnel/ford attributes from short sections of road so they can be merged
        visible_brunnel(geometry, is_bridge, 10) AS is_bridge,
        visible_brunnel(geometry, is_tunnel, 10) AS is_tunnel,
        visible_brunnel(geometry, is_ford, 10) AS is_ford,
        expressway,
        z_order,
        bicycle,
        foot,
        horse,
        mtb_scale,
        sac_scale,
        access,
        toll,
        visible_layer(geometry, layer, 10) AS layer
    FROM osm_transportation_merge_linestring_gen_z10
    WHERE full_update IS TRUE OR EXISTS(
            SELECT NULL FROM transportation.changes_z9_z10
            WHERE transportation.changes_z9_z10.is_old IS FALSE AND
                  transportation.changes_z9_z10.id = osm_transportation_merge_linestring_gen_z10.id
            )
    ON CONFLICT (id) DO UPDATE SET osm_id = excluded.osm_id, highway = excluded.highway, network = excluded.network,
                                   construction = excluded.construction, is_bridge = excluded.is_bridge,
                                   is_tunnel = excluded.is_tunnel, is_ford = excluded.is_ford,
                                   expressway = excluded.expressway, z_order = excluded.z_order,
                                   bicycle = excluded.bicycle, foot = excluded.foot, horse = excluded.horse,
                                   mtb_scale = excluded.mtb_scale, sac_scale = excluded.sac_scale,
                                   access = excluded.access, toll = excluded.toll, layer = excluded.layer;

    -- noinspection SqlWithoutWhere
    DELETE FROM transportation.changes_z9_z10;

    RAISE LOG 'Refresh transportation z9 10 done in %', age(clock_timestamp(), t);
END;
$$ LANGUAGE plpgsql;

-- Ensure tables are emtpy if they haven't been created
TRUNCATE osm_transportation_merge_linestring_gen_z10;
TRUNCATE osm_transportation_merge_linestring_gen_z9;

SELECT insert_transportation_merge_linestring_gen_z10(TRUE);

-- Geometry Indexes
CREATE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z10_geometry_idx
    ON osm_transportation_merge_linestring_gen_z10 USING gist (geometry);
CREATE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z9_geometry_idx
    ON osm_transportation_merge_linestring_gen_z9 USING gist (geometry);

-- etldoc: osm_transportation_merge_linestring_gen_z9 -> osm_transportation_merge_linestring_gen_z8
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z8(
    geometry geometry,
    id SERIAL,
    osm_id bigint,
    source_ids int[],
    highway character varying,
    network character varying,
    construction character varying,
    is_bridge boolean,
    is_tunnel boolean,
    is_ford boolean,
    expressway boolean,
    z_order integer
);

ALTER TABLE osm_transportation_merge_linestring_gen_z8 ADD COLUMN IF NOT EXISTS source_ids bigint[];

-- Create osm_transportation_merge_linestring_gen_z7 as a copy of osm_transportation_merge_linestring_gen_z8 but
-- drop the "source_ids" column. This can be done because z7 to z5 tables are only simplified and not merged,
-- therefore relations to sources are direct via the id column.
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z7
    (LIKE osm_transportation_merge_linestring_gen_z8);
ALTER TABLE osm_transportation_merge_linestring_gen_z7 DROP COLUMN IF EXISTS source_ids;

-- Create osm_transportation_merge_linestring_gen_z6 as a copy of osm_transportation_merge_linestring_gen_z7
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z6
    (LIKE osm_transportation_merge_linestring_gen_z7);

-- Create osm_transportation_merge_linestring_gen_z5 as a copy of osm_transportation_merge_linestring_gen_z6
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z5
    (LIKE osm_transportation_merge_linestring_gen_z6);

-- Create osm_transportation_merge_linestring_gen_z4 as a copy of osm_transportation_merge_linestring_gen_z5
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z4
    (LIKE osm_transportation_merge_linestring_gen_z5);

-- Create OneToMany-Relation-Table storing relations of a Merged-LineString in table
-- osm_transportation_merge_linestring_gen_z8 to Source-LineStrings from table
-- osm_transportation_merge_linestring_gen_z9
CREATE TABLE IF NOT EXISTS osm_transportation_merge_linestring_gen_z8_source_ids(
    id int,
    source_id bigint,
    PRIMARY KEY (id, source_id)
);

-- Ensure tables are emtpy if they haven't been created
TRUNCATE osm_transportation_merge_linestring_gen_z8;
TRUNCATE osm_transportation_merge_linestring_gen_z8_source_ids;

-- Indexes for filling and updating osm_transportation_merge_linestring_gen_z8 table
CREATE UNIQUE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z9_update_partial_idx
    ON osm_transportation_merge_linestring_gen_z9 (id)
    WHERE (
        highway IN ('motorway', 'trunk', 'primary') OR
        construction IN ('motorway', 'trunk', 'primary')
    ) AND ST_IsValid(geometry) AND access IS NULL;

-- Analyze populated table with indexes
ANALYZE osm_transportation_merge_linestring_gen_z9;

-- Merge LineStrings from osm_transportation_merge_linestring_gen_z9 by grouping them and creating intersecting
-- clusters of each group via ST_ClusterDBSCAN
INSERT INTO osm_transportation_merge_linestring_gen_z8(geometry, source_ids, highway, network, construction, is_bridge,
                                                       is_tunnel, is_ford, expressway, z_order)
SELECT (ST_Dump(ST_Simplify(ST_LineMerge(ST_Union(geometry)), ZRes(10)))).geom AS geometry,
       -- We use St_Union instead of St_Collect to ensure no overlapping points exist within the geometries to
       -- merge. https://postgis.net/docs/ST_Union.html
       -- ST_LineMerge only merges across singular intersections and groups its output into a MultiLineString if
       -- more than two LineStrings form an intersection or no intersection could be found.
       -- https://postgis.net/docs/ST_LineMerge.html
       -- In order to not end up with a mixture of LineStrings and MultiLineStrings we dump eventual
       -- MultiLineStrings via ST_Dump. https://postgis.net/docs/ST_Dump.html
       array_agg(id) AS source_ids,
       -- Temporary Merged-LineString to Source-LineStrings-ID column to store relations before they have been
       -- intersected
       highway,
       network,
       construction,
       is_bridge,
       is_tunnel,
       is_ford,
       expressway,
       min(z_order) as z_order
FROM (
    SELECT osm_highway_linestring_normalized_brunnel_z9.*,
           -- Get intersecting clusters by setting minimum distance to 0 and minimum intersecting points to 1
           -- https://postgis.net/docs/ST_ClusterDBSCAN.html
           ST_ClusterDBSCAN(geometry, 0, 1) OVER (
               PARTITION BY highway, network, construction, is_bridge, is_tunnel, is_ford, expressway
           ) AS cluster,
           -- ST_ClusterDBSCAN returns an increasing integer as the cluster-ids within each partition starting at 0.
           -- This leads to clusters having the same ID across multiple partitions therefore we generate a
           -- Cluster-Group-ID by utilizing the DENSE_RANK function sorted over the partition columns.
           DENSE_RANK() OVER (
               ORDER BY highway, network, construction, is_bridge, is_tunnel, is_ford, expressway
           ) as cluster_group
    FROM (
        -- Remove bridge/tunnel/ford attributes from short sections of road so they can be merged
        SELECT id,
               geometry,
               highway,
               network,
               construction,
               visible_brunnel(geometry, is_bridge, 9) AS is_bridge,
               visible_brunnel(geometry, is_tunnel, 9) AS is_tunnel,
               visible_brunnel(geometry, is_ford, 9) AS is_ford,
               expressway,
               z_order
        FROM osm_transportation_merge_linestring_gen_z9
        WHERE (
            highway IN ('motorway', 'trunk', 'primary') OR
            construction IN ('motorway', 'trunk', 'primary')
        ) AND ST_IsValid(geometry) AND access IS NULL
    ) osm_highway_linestring_normalized_brunnel_z9
) q
GROUP BY cluster_group, cluster, highway, network, construction, is_bridge, is_tunnel, is_ford, expressway;

-- Geometry Index
CREATE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z8_geometry_idx
    ON osm_transportation_merge_linestring_gen_z8 USING gist (geometry);

-- Create Primary-Keys for osm_transportation_merge_linestring_gen_z8/z7/z6/z5/z4 tables
DO $$
BEGIN
    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_merge_linestring_gen_z8' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_merge_linestring_gen_z8 ADD PRIMARY KEY (id);
    END IF;

    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_merge_linestring_gen_z7' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_merge_linestring_gen_z7 ADD PRIMARY KEY (id);
    END IF;

    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_merge_linestring_gen_z6' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_merge_linestring_gen_z6 ADD PRIMARY KEY (id);
    END IF;

    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_merge_linestring_gen_z5' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_merge_linestring_gen_z5 ADD PRIMARY KEY (id);
    END IF;

    IF NOT EXISTS (
        SELECT constraint_name
        FROM information_schema.table_constraints
        WHERE table_name = 'osm_transportation_merge_linestring_gen_z4' AND constraint_type = 'PRIMARY KEY'
    ) THEN
        ALTER TABLE osm_transportation_merge_linestring_gen_z4 ADD PRIMARY KEY (id);
    END IF;
END;
$$ LANGUAGE plpgsql;

-- Indexes which can be utilized during full-update for queries originating from
-- insert_transportation_merge_linestring_gen_z7() function
CREATE UNIQUE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z8_update_partial_idx
    ON osm_transportation_merge_linestring_gen_z8 (id)
    WHERE ST_Length(geometry) > 50;

-- Analyze populated table with indexes
ANALYZE osm_transportation_merge_linestring_gen_z8;

-- Store OSM-IDs of Source-LineStrings by intersecting Merged-LineStrings with their sources. This required because
-- ST_LineMerge only merges across singular intersections and groups its output into a MultiLineString if
-- more than two LineStrings form an intersection or no intersection could be found.
-- Execute after indexes have been created on osm_transportation_merge_linestring_gen_z11 to improve performance
INSERT INTO osm_transportation_merge_linestring_gen_z8_source_ids (id, source_id)
SELECT m.id, m.source_id
FROM (
    SELECT id, unnest(source_ids) AS source_id, geometry
    FROM osm_transportation_merge_linestring_gen_z8
) m
JOIN osm_transportation_merge_linestring_gen_z9 s ON (m.source_id = s.id)
WHERE ST_Intersects(s.geometry, m.geometry)
ON CONFLICT (id, source_id) DO NOTHING;

-- Drop temporary Merged-LineString to Source-LineStrings-ID column
ALTER TABLE osm_transportation_merge_linestring_gen_z8 DROP COLUMN IF EXISTS source_ids;

CREATE TABLE IF NOT EXISTS transportation.changes_z4_z5_z6_z7
(
    is_old boolean,
    id int,
    PRIMARY KEY (is_old, id)
);

CREATE OR REPLACE FUNCTION insert_transportation_merge_linestring_gen_z7(full_update boolean) RETURNS void AS
$$
DECLARE
    t TIMESTAMP WITH TIME ZONE := clock_timestamp();
BEGIN
    RAISE LOG 'Refresh transportation z4 z5 z6 z7';

    -- Analyze tracking and source tables before performing update
    ANALYZE transportation.changes_z4_z5_z6_z7;
    ANALYZE osm_transportation_merge_linestring_gen_z8;

    -- Remove entries which have been deleted from source table
    DELETE FROM osm_transportation_merge_linestring_gen_z7
    USING transportation.changes_z4_z5_z6_z7
    WHERE full_update IS TRUE OR (
        transportation.changes_z4_z5_z6_z7.is_old IS TRUE AND
        transportation.changes_z4_z5_z6_z7.id = osm_transportation_merge_linestring_gen_z7.id
    );

    -- etldoc: osm_transportation_merge_linestring_gen_z8 -> osm_transportation_merge_linestring_gen_z7
    INSERT INTO osm_transportation_merge_linestring_gen_z7
    WITH roads_z8 AS (
        SELECT  id,
                osm_id,
                ST_SnapToGrid(
                    ST_Node(
                        ST_Collect(
                            ST_Simplify(geometry, ZRes(9))
                            )
                        ), ZRes(9)
                    ) AS geometry,
                highway, 
                NULLIF(network, '') as network,
                construction,
                is_bridge, 
                is_tunnel, 
                is_ford,
                expressway,
                z_order
        FROM osm_transportation_merge_linestring_gen_z8
        GROUP BY id, osm_id, highway, construction, network, is_bridge, is_tunnel, is_ford, expressway, z_order
        ),
    roads_z8_merge AS (
        SELECT  id,
                osm_id,
                ST_LineMerge(
                    ST_Union(geometry)
                    ) AS geometry,
                highway,
                network,
                construction,
                is_bridge,
                is_tunnel,
                is_ford,
                expressway,
                z_order
    FROM roads_z8
    GROUP BY id, osm_id, highway, network, construction, is_bridge, is_tunnel, is_ford, expressway, z_order
    )

    SELECT  CASE
             WHEN ST_StartPoint(geometry) = ST_EndPoint(geometry) 
                 THEN ST_RemovePoint(geometry, ST_NPoints(geometry) - 1)
             ELSE geometry
            END AS geometry,  
            id,
            osm_id,
            highway,
            network,
            construction,
            -- Remove bridge/tunnel/ford attributes from short sections of road so they can be merged
            visible_brunnel(geometry, is_bridge, 8) AS is_bridge,
            visible_brunnel(geometry, is_tunnel, 8) AS is_tunnel,
            visible_brunnel(geometry, is_ford, 8) AS is_ford,
            expressway,
            z_order
    FROM roads_z8_merge
        -- Current view: motorway/trunk/primary
    WHERE
        (full_update IS TRUE OR EXISTS(
            SELECT NULL FROM transportation.changes_z4_z5_z6_z7
            WHERE transportation.changes_z4_z5_z6_z7.is_old IS FALSE AND
                  transportation.changes_z4_z5_z6_z7.id = roads_z8_merge.id
        )) AND
        (ST_Length(geometry) > 50)
    ON CONFLICT (id) DO UPDATE SET osm_id = excluded.osm_id, highway = excluded.highway, network = excluded.network,
                                   construction = excluded.construction, is_bridge = excluded.is_bridge,
                                   is_tunnel = excluded.is_tunnel, is_ford = excluded.is_ford,
                                   expressway = excluded.expressway, z_order = excluded.z_order;

    -- Analyze source table
    ANALYZE osm_transportation_merge_linestring_gen_z7;

    -- Remove entries which have been deleted from source table
    DELETE FROM osm_transportation_merge_linestring_gen_z6
    USING transportation.changes_z4_z5_z6_z7
    WHERE full_update IS TRUE OR (
        transportation.changes_z4_z5_z6_z7.is_old IS TRUE AND
        transportation.changes_z4_z5_z6_z7.id = osm_transportation_merge_linestring_gen_z6.id
    );

    -- etldoc: osm_transportation_merge_linestring_gen_z7 -> osm_transportation_merge_linestring_gen_z6
    INSERT INTO osm_transportation_merge_linestring_gen_z6
    SELECT ST_Simplify(geometry, ZRes(8)) AS geometry,
        id,
        osm_id,
        highway,
        network,
        construction,
        -- Remove bridge/tunnel/ford attributes from short sections of road so they can be merged
        visible_brunnel(geometry, is_bridge, 7) AS is_bridge,
        visible_brunnel(geometry, is_tunnel, 7) AS is_tunnel,
        visible_brunnel(geometry, is_ford, 7) AS is_ford,
        expressway,
        z_order
    FROM osm_transportation_merge_linestring_gen_z7
    -- Current view: motorway/trunk/primary
    WHERE
        (full_update IS TRUE OR EXISTS(
            SELECT NULL FROM transportation.changes_z4_z5_z6_z7
            WHERE transportation.changes_z4_z5_z6_z7.is_old IS FALSE AND
                  transportation.changes_z4_z5_z6_z7.id = osm_transportation_merge_linestring_gen_z7.id
        )) AND
        (highway IN ('motorway', 'trunk') OR construction IN ('motorway', 'trunk')) AND
        ST_Length(geometry) > 100
    ON CONFLICT (id) DO UPDATE SET osm_id = excluded.osm_id, highway = excluded.highway, network = excluded.network,
                                   construction = excluded.construction, is_bridge = excluded.is_bridge,
                                   is_tunnel = excluded.is_tunnel, is_ford = excluded.is_ford,
                                   expressway = excluded.expressway, z_order = excluded.z_order;

    -- Analyze source table
    ANALYZE osm_transportation_merge_linestring_gen_z6;

    -- Remove entries which have been deleted from source table
    DELETE FROM osm_transportation_merge_linestring_gen_z5
    USING transportation.changes_z4_z5_z6_z7
    WHERE full_update IS TRUE OR (
        transportation.changes_z4_z5_z6_z7.is_old IS TRUE AND
        transportation.changes_z4_z5_z6_z7.id = osm_transportation_merge_linestring_gen_z5.id
        );

    -- etldoc: osm_transportation_merge_linestring_gen_z6 -> osm_transportation_merge_linestring_gen_z5
    INSERT INTO osm_transportation_merge_linestring_gen_z5
    SELECT ST_Simplify(geometry, ZRes(7)) AS geometry,
        id,
        osm_id,
        highway,
        network,
        construction,
        -- Remove bridge/tunnel/ford attributes from short sections of road so they can be merged
        visible_brunnel(geometry, is_bridge, 6) AS is_bridge,
        visible_brunnel(geometry, is_tunnel, 6) AS is_tunnel,
        visible_brunnel(geometry, is_ford, 6) AS is_ford,
        expressway,
        z_order
    FROM osm_transportation_merge_linestring_gen_z6
    WHERE
        (full_update IS TRUE OR EXISTS(
            SELECT NULL FROM transportation.changes_z4_z5_z6_z7
            WHERE transportation.changes_z4_z5_z6_z7.is_old IS FALSE AND
                  transportation.changes_z4_z5_z6_z7.id = osm_transportation_merge_linestring_gen_z6.id
        )) AND
        -- Current view: all motorways and trunks of national-importance
        (highway = 'motorway'
            OR construction = 'motorway'
            -- Allow trunk roads that are part of a nation's most important route network to show at z5
            OR (highway = 'trunk' AND osm_national_network(network))
        ) AND
        ST_Length(geometry) > 500
    ON CONFLICT (id) DO UPDATE SET osm_id = excluded.osm_id, highway = excluded.highway, network = excluded.network,
                                   construction = excluded.construction, is_bridge = excluded.is_bridge,
                                   is_tunnel = excluded.is_tunnel, is_ford = excluded.is_ford,
                                   expressway = excluded.expressway, z_order = excluded.z_order;

    -- Analyze source table
    ANALYZE osm_transportation_merge_linestring_gen_z5;

    -- Remove entries which have been deleted from source table
    DELETE FROM osm_transportation_merge_linestring_gen_z4
    USING transportation.changes_z4_z5_z6_z7
    WHERE full_update IS TRUE OR (
        transportation.changes_z4_z5_z6_z7.is_old IS TRUE AND
        transportation.changes_z4_z5_z6_z7.id = osm_transportation_merge_linestring_gen_z4.id
    );

    -- etldoc: osm_transportation_merge_linestring_gen_z5 -> osm_transportation_merge_linestring_gen_z4
    INSERT INTO osm_transportation_merge_linestring_gen_z4
    SELECT ST_Simplify(geometry, ZRes(6)) AS geometry,
        id,
        osm_id,
        highway,
        network,
        construction,
        visible_brunnel(geometry, is_bridge, 5) AS is_bridge,
        visible_brunnel(geometry, is_tunnel, 5) AS is_tunnel,
        visible_brunnel(geometry, is_ford, 5) AS is_ford,
        expressway,
        z_order
    FROM osm_transportation_merge_linestring_gen_z5
    WHERE
        (full_update IS TRUE OR EXISTS(
            SELECT NULL FROM transportation.changes_z4_z5_z6_z7
            WHERE transportation.changes_z4_z5_z6_z7.is_old IS FALSE AND
                  transportation.changes_z4_z5_z6_z7.id = osm_transportation_merge_linestring_gen_z5.id
        )) AND
        -- All motorways without network (e.g. EU, Asia, South America)
        ((highway = 'motorway' OR construction = 'motorway') AND (network is NULL or network = '')
        ) OR 
        -- All roads in network included in osm_national_network except gb-trunk and us-highway
		( (osm_national_network(network) AND network NOT IN ('gb-trunk', 'us-highway')
        )) AND
        -- Current view: national-importance motorways and trunks
        ST_Length(geometry) > 1000
    ON CONFLICT (id) DO UPDATE SET osm_id = excluded.osm_id, highway = excluded.highway, network = excluded.network,
                                   construction = excluded.construction, is_bridge = excluded.is_bridge,
                                   is_tunnel = excluded.is_tunnel, is_ford = excluded.is_ford,
                                   expressway = excluded.expressway, z_order = excluded.z_order;

    -- noinspection SqlWithoutWhere
    DELETE FROM transportation.changes_z4_z5_z6_z7;

    RAISE LOG 'Refresh transportation z4 z5 z6 z7 done in %', age(clock_timestamp(), t);
END;
$$ LANGUAGE plpgsql;

-- Ensure tables are emtpy if they haven't been created
TRUNCATE osm_transportation_merge_linestring_gen_z7;
TRUNCATE osm_transportation_merge_linestring_gen_z6;
TRUNCATE osm_transportation_merge_linestring_gen_z5;
TRUNCATE osm_transportation_merge_linestring_gen_z4;

SELECT insert_transportation_merge_linestring_gen_z7(TRUE);

-- Indexes for queries originating from insert_transportation_merge_linestring_gen_z7() function
CREATE UNIQUE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z7_update_partial_idx
    ON osm_transportation_merge_linestring_gen_z7 (id)
    WHERE (highway IN ('motorway', 'trunk') OR construction IN ('motorway', 'trunk')) AND
          ST_Length(geometry) > 100;
CREATE UNIQUE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z6_update_partial_idx
    ON osm_transportation_merge_linestring_gen_z6 (id)
    WHERE (highway = 'motorway'
            OR construction = 'motorway'
            OR (highway = 'trunk' AND osm_national_network(network))
        ) AND
        ST_Length(geometry) > 500;
CREATE UNIQUE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z5_update_partial_idx
    ON osm_transportation_merge_linestring_gen_z5 (id)
    WHERE osm_national_network(network) AND ST_Length(geometry) > 1000;

-- Geometry Indexes
CREATE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z7_geometry_idx
    ON osm_transportation_merge_linestring_gen_z7 USING gist (geometry);
CREATE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z6_geometry_idx
    ON osm_transportation_merge_linestring_gen_z6 USING gist (geometry);
CREATE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z5_geometry_idx
    ON osm_transportation_merge_linestring_gen_z5 USING gist (geometry);
CREATE INDEX IF NOT EXISTS osm_transportation_merge_linestring_gen_z4_geometry_idx
    ON osm_transportation_merge_linestring_gen_z4 USING gist (geometry);


-- Handle updates on
-- osm_highway_linestring_gen_z11 -> osm_transportation_merge_linestring_gen_z11
-- osm_transportation_merge_linestring_gen_z11 -> osm_transportation_merge_linestring_gen_z10
-- osm_transportation_merge_linestring_gen_z11 -> osm_transportation_merge_linestring_gen_z9
CREATE OR REPLACE AGGREGATE array_cat_agg(anycompatiblearray) (
  SFUNC=array_cat,
  STYPE=anycompatiblearray,
  INITCOND = '{}'
);

CREATE TABLE IF NOT EXISTS transportation.changes_z11
(
    is_old boolean NULL,
    osm_id bigint,
    PRIMARY KEY (is_old, osm_id)
);

-- Store IDs of changed elements from osm_highway_linestring_gen_z11 table.
CREATE OR REPLACE FUNCTION transportation.store_gen_z11() RETURNS trigger AS
$$
BEGIN
    IF (tg_op = 'INSERT' OR tg_op = 'UPDATE') THEN
        INSERT INTO transportation.changes_z11(is_old, osm_id)
        VALUES (FALSE, new.osm_id)
        ON CONFLICT (is_old, osm_id) DO NOTHING;
    END IF;
    IF (tg_op = 'DELETE' OR tg_op = 'UPDATE') THEN
        INSERT INTO transportation.changes_z11(is_old, osm_id)
        VALUES (TRUE, old.osm_id)
        ON CONFLICT (is_old, osm_id) DO NOTHING;
    END IF;
    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

-- Store IDs of changed elements from osm_highway_linestring_gen_z9 table.
CREATE OR REPLACE FUNCTION transportation.store_merge_z11() RETURNS trigger AS
$$
BEGIN
    IF (tg_op = 'INSERT' OR tg_op = 'UPDATE') THEN
        INSERT INTO transportation.changes_z9_z10(is_old, id)
        VALUES (FALSE, new.id)
        ON CONFLICT (is_old, id) DO NOTHING;
    END IF;
    IF tg_op = 'DELETE' THEN
        INSERT INTO transportation.changes_z9_z10(is_old, id)
        VALUES (TRUE, old.id)
        ON CONFLICT (is_old, id) DO NOTHING;
    END IF;
    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

CREATE TABLE IF NOT EXISTS transportation.updates_z11
(
    id serial PRIMARY KEY,
    t text,
    UNIQUE (t)
);
CREATE OR REPLACE FUNCTION transportation.flag_z11() RETURNS trigger AS
$$
BEGIN
    INSERT INTO transportation.updates_z11(t) VALUES ('y') ON CONFLICT(t) DO NOTHING;
    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION transportation.refresh_z11() RETURNS trigger AS
$$
DECLARE
    t TIMESTAMP WITH TIME ZONE := clock_timestamp();
BEGIN
    RAISE LOG 'Refresh transportation z11';

    -- Analyze tracking and source tables before performing update
    ANALYZE transportation.changes_z11;
    ANALYZE osm_highway_linestring_gen_z11;

    -- Fetch updated and deleted Merged-LineString from relation-table filtering for each Merged-LineString which
    -- contains an updated Source-LineString.
    -- Additionally attach a list of Source-LineString-IDs to each Merged-LineString in order to unnest them later.
    CREATE TEMPORARY TABLE affected_merged_linestrings AS
    SELECT m.id, array_agg(source_id) AS source_ids
    FROM osm_transportation_merge_linestring_gen_z11_source_ids m
    WHERE EXISTS(
        SELECT NULL
        FROM transportation.changes_z11 c
        WHERE c.is_old IS TRUE AND c.osm_id = m.source_id
    )
    GROUP BY id;

    -- Analyze the created table to speed up subsequent queries
    ANALYZE affected_merged_linestrings;

    -- Delete all Merged-LineStrings which contained an updated or deleted Source-LineString
    DELETE
    FROM osm_transportation_merge_linestring_gen_z11 m
    USING affected_merged_linestrings
    WHERE affected_merged_linestrings.id = m.id;
    DELETE
    FROM osm_transportation_merge_linestring_gen_z11_source_ids m
    USING affected_merged_linestrings
    WHERE affected_merged_linestrings.id = m.id;

    -- Analyze the tables affected by the delete-query in order to speed up subsequent queries
    ANALYZE osm_transportation_merge_linestring_gen_z11;
    ANALYZE osm_transportation_merge_linestring_gen_z11_source_ids;

    -- Create a table containing all LineStrings which should be merged
    CREATE TEMPORARY TABLE linestrings_to_merge AS
    -- Add all Source-LineStrings affected by this update
    SELECT osm_highway_linestring_gen_z11.osm_id, NULL::INTEGER AS id, NULL::BIGINT[] AS source_ids,
           geometry, highway, network, construction,
           visible_brunnel(geometry, is_bridge, 11) AS is_bridge,
           visible_brunnel(geometry, is_tunnel, 11) AS is_tunnel,
           visible_brunnel(geometry, is_ford, 11) AS is_ford,
           expressway, bicycle, foot, horse, mtb_scale, sac_scale,
           CASE WHEN access IN ('private', 'no') THEN 'no' ELSE NULL::text END AS access, toll,
           visible_layer(geometry, layer, 11) AS layer, z_order
    -- Table containing the IDs of all Source-LineStrings affected by this update
    FROM (
        -- Get Source-LineString-IDs of deleted or updated elements
        SELECT unnest(affected_merged_linestrings.source_ids)::bigint AS source_id FROM affected_merged_linestrings
        UNION
        -- Get Source-LineString-IDs of inserted or updated elements
        SELECT osm_id AS source_id FROM transportation.changes_z11 WHERE is_old IS FALSE
        ORDER BY source_id
    ) affected_source_linestrings
    JOIN osm_highway_linestring_gen_z11 ON (
        affected_source_linestrings.source_id = osm_highway_linestring_gen_z11.osm_id
    );

    -- Drop temporary tables early to save resources
    DROP TABLE affected_merged_linestrings;

    -- Analyze the created table to speed up subsequent queries
    ANALYZE linestrings_to_merge;

    -- Add all Merged-LineStrings intersecting with Source-LineStrings affected by this update
    INSERT INTO linestrings_to_merge
    SELECT NULL::BIGINT AS osm_id, m.id,
           ARRAY(
               SELECT s.source_id FROM osm_transportation_merge_linestring_gen_z11_source_ids s WHERE s.id = m.id
           )::BIGINT[] AS source_ids, m.geometry, m.highway, m.network, m.construction,
           visible_brunnel(m.geometry, m.is_bridge, 11) AS is_bridge,
           visible_brunnel(m.geometry, m.is_tunnel, 11) AS is_tunnel,
           visible_brunnel(m.geometry, m.is_ford, 11) AS is_ford,
           m.expressway, m.bicycle, m.foot, m.horse, m.mtb_scale, m.sac_scale, m.access, m.toll,
           visible_layer(m.geometry, m.layer, 11) AS layer, m.z_order
    FROM linestrings_to_merge
    JOIN osm_transportation_merge_linestring_gen_z11 m ON (ST_Intersects(linestrings_to_merge.geometry, m.geometry));

    -- Analyze the created table to speed up subsequent queries
    ANALYZE linestrings_to_merge;

    -- Delete all Merged-LineStrings intersecting with Source-LineStrings affected by this update.
    -- We can use the linestrings_to_merge table since Source-LineStrings affected by this update and present in the
    -- table will have their ID-Column set to NULL by the previous query.
    DELETE
    FROM osm_transportation_merge_linestring_gen_z11 m
    USING linestrings_to_merge
    WHERE m.id = linestrings_to_merge.id;
    DELETE
    FROM osm_transportation_merge_linestring_gen_z11_source_ids m
    USING linestrings_to_merge
    WHERE linestrings_to_merge.id = m.id;

    -- Create table containing all LineStrings to and create clusters of intersecting LineStrings partitioned by their
    -- groups
    CREATE TEMPORARY TABLE clustered_linestrings_to_merge AS
    SELECT *,
           -- Get intersecting clusters by setting minimum distance to 0 and minimum intersecting points to 1
           -- https://postgis.net/docs/ST_ClusterDBSCAN.html
           ST_ClusterDBSCAN(geometry, 0, 1) OVER (
               PARTITION BY highway, network, construction, is_bridge, is_tunnel, is_ford, expressway, bicycle, foot,
               horse, mtb_scale, sac_scale, access, toll, layer
           ) AS cluster,
           -- ST_ClusterDBSCAN returns an increasing integer as the cluster-ids within each partition starting at 0.
           -- This leads to clusters having the same ID across multiple partitions therefore we generate a
           -- Cluster-Group-ID by utilizing the DENSE_RANK function sorted over the partition columns.
           DENSE_RANK() OVER (
               ORDER BY highway, network, construction, is_bridge, is_tunnel, is_ford, expressway, bicycle, foot, horse,
               mtb_scale, sac_scale, access, toll, layer
           ) as cluster_group
    FROM linestrings_to_merge;

    -- Drop temporary tables early to save resources
    DROP TABLE linestrings_to_merge;

    -- Create index on cluster columns and analyze the created table to speed up subsequent queries
    CREATE INDEX ON clustered_linestrings_to_merge (cluster_group, cluster);
    ANALYZE clustered_linestrings_to_merge;

    -- Create temporary Merged-LineString to Source-LineStrings-ID columns to store relations before they have been
    -- intersected
    ALTER TABLE osm_transportation_merge_linestring_gen_z11 ADD COLUMN IF NOT EXISTS new_source_ids BIGINT[];
    ALTER TABLE osm_transportation_merge_linestring_gen_z11 ADD COLUMN IF NOT EXISTS old_source_ids BIGINT[];

    WITH inserted_linestrings AS (
        -- Merge LineStrings of each cluster and insert them
        INSERT INTO osm_transportation_merge_linestring_gen_z11(geometry, new_source_ids, old_source_ids, highway,
                                                                network, construction, is_bridge, is_tunnel, is_ford,
                                                                expressway, z_order, bicycle, foot, horse, mtb_scale,
                                                                sac_scale, access, toll, layer)
        SELECT (ST_Dump(ST_LineMerge(ST_Union(geometry)))).geom AS geometry,
               -- We use St_Union instead of St_Collect to ensure no overlapping points exist within the geometries to
               -- merge. https://postgis.net/docs/ST_Union.html
               -- ST_LineMerge only merges across singular intersections and groups its output into a MultiLineString if
               -- more than two LineStrings form an intersection or no intersection could be found.
               -- https://postgis.net/docs/ST_LineMerge.html
               -- In order to not end up with a mixture of LineStrings and MultiLineStrings we dump eventual
               -- MultiLineStrings via ST_Dump. https://postgis.net/docs/ST_Dump.html
               coalesce( array_agg(osm_id) FILTER (WHERE osm_id IS NOT NULL), '{}' )::BIGINT[] AS new_source_ids,
               array_cat_agg(source_ids)::BIGINT[] AS old_source_ids,
               highway,
               network,
               construction,
               is_bridge,
               is_tunnel,
               is_ford,
               expressway,
               min(z_order) as z_order,
               bicycle,
               foot,
               horse,
               mtb_scale,
               sac_scale,
               access,
               toll,
               layer
        FROM clustered_linestrings_to_merge
        GROUP BY cluster_group, cluster, highway, network, construction, is_bridge, is_tunnel, is_ford, expressway,
                 bicycle, foot, horse, mtb_scale, sac_scale, access, toll, layer
        RETURNING id, new_source_ids, old_source_ids, geometry
    )
    -- Store OSM-IDs of Source-LineStrings by intersecting Merged-LineStrings with their sources.
    -- This is required because ST_LineMerge only merges across singular intersections and groups its output into a
    -- MultiLineString if more than two LineStrings form an intersection or no intersection could be found.
    INSERT INTO osm_transportation_merge_linestring_gen_z11_source_ids (id, source_id)
    SELECT m.id, source_id
    FROM (
        SELECT id, source_id, geometry
        FROM inserted_linestrings
        CROSS JOIN LATERAL (
            SELECT DISTINCT all_source_ids.source_id
            FROM unnest(
                array_cat(inserted_linestrings.new_source_ids, inserted_linestrings.old_source_ids)
            ) AS all_source_ids(source_id)
        ) source_ids
    ) m
    JOIN osm_highway_linestring_gen_z11 s ON (m.source_id = s.osm_id)
    WHERE ST_Intersects(s.geometry, m.geometry)
    ON CONFLICT (id, source_id) DO NOTHING;

    -- Cleanup remaining table
    DROP TABLE clustered_linestrings_to_merge;

    -- Drop  temporary Merged-LineString to Source-LineStrings-ID columns
    ALTER TABLE osm_transportation_merge_linestring_gen_z11 DROP COLUMN IF EXISTS new_source_ids;
    ALTER TABLE osm_transportation_merge_linestring_gen_z11 DROP COLUMN IF EXISTS old_source_ids;

    -- noinspection SqlWithoutWhere
    DELETE FROM transportation.changes_z11;
    -- noinspection SqlWithoutWhere
    DELETE FROM transportation.updates_z11;

    RAISE LOG 'Refresh transportation z11 done in %', age(clock_timestamp(), t);

    -- Update z10 and z9 tables
    PERFORM insert_transportation_merge_linestring_gen_z10(FALSE);

    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER trigger_store_transportation_highway_linestring_gen_z11
    AFTER INSERT OR UPDATE OR DELETE
    ON osm_highway_linestring_gen_z11
    FOR EACH ROW
EXECUTE PROCEDURE transportation.store_gen_z11();

CREATE TRIGGER trigger_store_osm_transportation_merge_linestring_gen_z11
    AFTER INSERT OR UPDATE OR DELETE
    ON osm_transportation_merge_linestring_gen_z11
    FOR EACH ROW
EXECUTE PROCEDURE transportation.store_merge_z11();

CREATE TRIGGER trigger_flag_transportation_z11
    AFTER INSERT OR UPDATE OR DELETE
    ON osm_highway_linestring_gen_z11
    FOR EACH STATEMENT
EXECUTE PROCEDURE transportation.flag_z11();

CREATE CONSTRAINT TRIGGER trigger_refresh_z11
    AFTER INSERT
    ON transportation.updates_z11
    INITIALLY DEFERRED
    FOR EACH ROW
EXECUTE PROCEDURE transportation.refresh_z11();


-- Handle updates on
-- osm_transportation_merge_linestring_gen_z9 -> osm_transportation_merge_linestring_gen_z8
-- osm_transportation_merge_linestring_gen_z8 -> osm_transportation_merge_linestring_gen_z7
-- osm_transportation_merge_linestring_gen_z8 -> osm_transportation_merge_linestring_gen_z6
-- osm_transportation_merge_linestring_gen_z8 -> osm_transportation_merge_linestring_gen_z5
-- osm_transportation_merge_linestring_gen_z8 -> osm_transportation_merge_linestring_gen_z4

CREATE TABLE IF NOT EXISTS transportation.changes_z9
(
    is_old boolean,
    id bigint,
    PRIMARY KEY (is_old, id)
);

-- Store IDs of changed elements from osm_highway_linestring_gen_z9 table.
CREATE OR REPLACE FUNCTION transportation.store_z9() RETURNS trigger AS
$$
BEGIN
    IF (tg_op = 'INSERT' OR tg_op = 'UPDATE') THEN
        INSERT INTO transportation.changes_z9(is_old, id)
        VALUES (FALSE, new.id)
        ON CONFLICT (is_old, id) DO NOTHING;
    END IF;
    IF (tg_op = 'DELETE' OR tg_op = 'UPDATE') THEN
        INSERT INTO transportation.changes_z9(is_old, id)
        VALUES (TRUE, old.id)
        ON CONFLICT (is_old, id) DO NOTHING;
    END IF;
    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

-- Store IDs of changed elements from osm_highway_linestring_gen_z8 table.
CREATE OR REPLACE FUNCTION transportation.store_z8() RETURNS trigger AS
$$
BEGIN
    IF (tg_op = 'INSERT' OR tg_op = 'UPDATE') THEN
        INSERT INTO transportation.changes_z4_z5_z6_z7(is_old, id)
        VALUES (FALSE, new.id)
        ON CONFLICT (is_old, id) DO NOTHING;
    END IF;
    IF tg_op = 'DELETE' THEN
        INSERT INTO transportation.changes_z4_z5_z6_z7(is_old, id)
        VALUES (TRUE, old.id)
        ON CONFLICT (is_old, id) DO NOTHING;
    END IF;
    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

CREATE TABLE IF NOT EXISTS transportation.updates_z9
(
    id serial PRIMARY KEY,
    t text,
    UNIQUE (t)
);
CREATE OR REPLACE FUNCTION transportation.flag_z9() RETURNS trigger AS
$$
BEGIN
    INSERT INTO transportation.updates_z9(t) VALUES ('y') ON CONFLICT(t) DO NOTHING;
    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION transportation.refresh_z8() RETURNS trigger AS
$$
DECLARE
    t TIMESTAMP WITH TIME ZONE := clock_timestamp();
BEGIN
    RAISE LOG 'Refresh transportation z8';

    -- Analyze tracking and source tables before performing update
    ANALYZE transportation.changes_z9;
    ANALYZE osm_transportation_merge_linestring_gen_z9;

    -- Fetch updated and deleted Merged-LineString from relation-table filtering for each Merged-LineString which
    -- contains an updated Source-LineString.
    -- Additionally attach a list of Source-LineString-IDs to each Merged-LineString in order to unnest them later.
    CREATE TEMPORARY TABLE affected_merged_linestrings AS
    SELECT m.id, array_agg(source_id) AS source_ids
    FROM osm_transportation_merge_linestring_gen_z8_source_ids m
    WHERE EXISTS(
        SELECT NULL
        FROM transportation.changes_z9 c
        WHERE c.is_old IS TRUE AND c.id = m.source_id
    )
    GROUP BY id;

    -- Analyze the created table to speed up subsequent queries
    ANALYZE affected_merged_linestrings;

    -- Delete all Merged-LineStrings which contained an updated or deleted Source-LineString
    DELETE
    FROM osm_transportation_merge_linestring_gen_z8 m
    USING affected_merged_linestrings
    WHERE affected_merged_linestrings.id = m.id;
    DELETE
    FROM osm_transportation_merge_linestring_gen_z8_source_ids m
    USING affected_merged_linestrings
    WHERE affected_merged_linestrings.id = m.id;

    -- Analyze the tables affected by the delete-query in order to speed up subsequent queries
    ANALYZE osm_transportation_merge_linestring_gen_z8;
    ANALYZE osm_transportation_merge_linestring_gen_z8_source_ids;

    -- Create a table containing all LineStrings which should be merged
    CREATE TEMPORARY TABLE linestrings_to_merge AS
    -- Add all Source-LineStrings affected by this update
    SELECT id AS source_id, NULL::INT AS id, NULL::INT[] AS source_ids, geometry, highway, network, construction,
           visible_brunnel(geometry, is_bridge, 9) AS is_bridge,
           visible_brunnel(geometry, is_tunnel, 9) AS is_tunnel,
           visible_brunnel(geometry, is_ford, 9) AS is_ford, expressway, z_order
    -- Create a table containing the IDs of all Source-LineStrings affected by this update
    FROM (
        -- Get Source-LineString-IDs of deleted or updated elements
        SELECT unnest(affected_merged_linestrings.source_ids)::bigint AS source_id FROM affected_merged_linestrings
        UNION
        -- Get Source-LineString-IDs of inserted or updated elements
        SELECT id AS source_id FROM transportation.changes_z9 WHERE transportation.changes_z9.is_old IS FALSE
        ORDER BY source_id
    ) affected_source_linestrings
    JOIN osm_transportation_merge_linestring_gen_z9 ON (
        affected_source_linestrings.source_id = osm_transportation_merge_linestring_gen_z9.id
    )
    WHERE (
        highway IN ('motorway', 'trunk', 'primary') OR
        construction IN ('motorway', 'trunk', 'primary')
    ) AND
    ST_IsValid(geometry) AND
    access IS NULL;

    -- Drop temporary tables early to save resources
    DROP TABLE affected_merged_linestrings;

    -- Analyze the created table to speed up subsequent queries
    ANALYZE linestrings_to_merge;

    -- Add all Merged-LineStrings intersecting with Source-LineStrings affected by this update
    INSERT INTO linestrings_to_merge
    SELECT NULL::INT AS source_id, m.id,
           ARRAY(
               SELECT s.source_id FROM osm_transportation_merge_linestring_gen_z8_source_ids s WHERE s.id = m.id
           )::INT[] AS source_ids, m.geometry, m.highway, m.network, m.construction,
           visible_brunnel(m.geometry, m.is_bridge, 9) AS is_bridge,
           visible_brunnel(m.geometry, m.is_tunnel, 9) AS is_tunnel,
           visible_brunnel(m.geometry, m.is_ford, 9) AS is_ford, m.expressway, m.z_order
    FROM linestrings_to_merge
    JOIN osm_transportation_merge_linestring_gen_z8 m ON (ST_Intersects(linestrings_to_merge.geometry, m.geometry));

    -- Analyze the created table to speed up subsequent queries
    ANALYZE linestrings_to_merge;

    -- Delete all Merged-LineStrings intersecting with Source-LineStrings affected by this update.
    -- We can use the linestrings_to_merge table since Source-LineStrings affected by this update and present in the
    -- table will have their ID-Column set to NULL by the previous query.
    DELETE
    FROM osm_transportation_merge_linestring_gen_z8 m
    USING linestrings_to_merge
    WHERE m.id = linestrings_to_merge.id;
    DELETE
    FROM osm_transportation_merge_linestring_gen_z8_source_ids m
    USING linestrings_to_merge
    WHERE m.id = linestrings_to_merge.id;

    -- Create table containing all LineStrings to and create clusters of intersecting LineStrings partitioned by their
    -- groups
    CREATE TEMPORARY TABLE clustered_linestrings_to_merge AS
    SELECT *,
           -- Get intersecting clusters by setting minimum distance to 0 and minimum intersecting points to 1
           -- https://postgis.net/docs/ST_ClusterDBSCAN.html
           ST_ClusterDBSCAN(geometry, 0, 1) OVER (
               PARTITION BY highway, network, construction, is_bridge, is_tunnel, is_ford, expressway
           ) AS cluster,
           -- ST_ClusterDBSCAN returns an increasing integer as the cluster-ids within each partition starting at 0.
           -- This leads to clusters having the same ID across multiple partitions therefore we generate a
           -- Cluster-Group-ID by utilizing the DENSE_RANK function sorted over the partition columns.
           DENSE_RANK() OVER (
               ORDER BY highway, network, construction, is_bridge, is_tunnel, is_ford, expressway
           ) as cluster_group
    FROM linestrings_to_merge;

    -- Drop temporary tables early to save resources
    DROP TABLE linestrings_to_merge;

    -- Create index on cluster columns and analyze the created table to speed up subsequent queries
    CREATE INDEX ON clustered_linestrings_to_merge (cluster_group, cluster);
    ANALYZE clustered_linestrings_to_merge;

    -- Create temporary Merged-LineString to Source-LineStrings-ID columns to store relations before they have been
    -- intersected
    ALTER TABLE osm_transportation_merge_linestring_gen_z8 ADD COLUMN IF NOT EXISTS new_source_ids INT[];
    ALTER TABLE osm_transportation_merge_linestring_gen_z8 ADD COLUMN IF NOT EXISTS old_source_ids INT[];

    WITH inserted_linestrings AS (
        -- Merge LineStrings of each cluster and insert them
        INSERT INTO osm_transportation_merge_linestring_gen_z8(geometry, new_source_ids, old_source_ids, highway,
                                                               network, construction, is_bridge, is_tunnel, is_ford,
                                                               expressway, z_order)
        SELECT (ST_Dump(ST_Simplify(ST_LineMerge(ST_Union(geometry)), ZRes(10)))).geom AS geometry,
               -- We use St_Union instead of St_Collect to ensure no overlapping points exist within the geometries to
               -- merge. https://postgis.net/docs/ST_Union.html
               -- ST_LineMerge only merges across singular intersections and groups its output into a MultiLineString if
               -- more than two LineStrings form an intersection or no intersection could be found.
               -- https://postgis.net/docs/ST_LineMerge.html
               -- In order to not end up with a mixture of LineStrings and MultiLineStrings we dump eventual
               -- MultiLineStrings via ST_Dump. https://postgis.net/docs/ST_Dump.html
            coalesce( array_agg(source_id) FILTER (WHERE source_id IS NOT NULL), '{}' )::INT[] AS new_source_ids,
            array_cat_agg(source_ids)::INT[] as old_source_ids,
            highway,
            network,
            construction,
            is_bridge,
            is_tunnel,
            is_ford,
            expressway,
            min(z_order) as z_order
        FROM clustered_linestrings_to_merge
        GROUP BY cluster_group, cluster, highway, network, construction, is_bridge, is_tunnel, is_ford, expressway
        RETURNING id, new_source_ids, old_source_ids, geometry
    )
    -- Store OSM-IDs of Source-LineStrings by intersecting Merged-LineStrings with their sources. This required because
    -- ST_LineMerge only merges across singular intersections and groups its output into a MultiLineString if
    -- more than two LineStrings form an intersection or no intersection could be found.
    INSERT INTO osm_transportation_merge_linestring_gen_z8_source_ids (id, source_id)
    SELECT m.id, m.source_id
    FROM (
        SELECT id, source_id, geometry
        FROM inserted_linestrings
        CROSS JOIN LATERAL (
            SELECT DISTINCT all_source_ids.source_id
            FROM unnest(
                array_cat(inserted_linestrings.new_source_ids, inserted_linestrings.old_source_ids)
            ) AS all_source_ids(source_id)
        ) source_ids
    ) m
    JOIN osm_transportation_merge_linestring_gen_z9 s ON (m.source_id = s.id)
    WHERE ST_Intersects(s.geometry, m.geometry)
    ON CONFLICT (id, source_id) DO NOTHING;

    -- Cleanup
    DROP TABLE clustered_linestrings_to_merge;

    -- Drop temporary Merged-LineString to Source-LineStrings-ID columns
    ALTER TABLE osm_transportation_merge_linestring_gen_z8 DROP COLUMN IF EXISTS new_source_ids;
    ALTER TABLE osm_transportation_merge_linestring_gen_z8 DROP COLUMN IF EXISTS old_source_ids;

    -- noinspection SqlWithoutWhere
    DELETE FROM transportation.changes_z9;
    -- noinspection SqlWithoutWhere
    DELETE FROM transportation.updates_z9;

    RAISE LOG 'Refresh transportation z8 done in %', age(clock_timestamp(), t);

    -- Update z7, z6, z5 and z4 tables
    PERFORM insert_transportation_merge_linestring_gen_z7(FALSE);

    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER trigger_store_transportation_highway_linestring_gen_z9
    AFTER INSERT OR UPDATE OR DELETE
    ON osm_transportation_merge_linestring_gen_z9
    FOR EACH ROW
EXECUTE PROCEDURE transportation.store_z9();

CREATE TRIGGER trigger_store_osm_transportation_merge_linestring_gen_z8
    AFTER INSERT OR UPDATE OR DELETE
    ON osm_transportation_merge_linestring_gen_z8
    FOR EACH ROW
EXECUTE PROCEDURE transportation.store_z8();

CREATE TRIGGER trigger_flag_transportation_z9
    AFTER INSERT OR UPDATE OR DELETE
    ON osm_transportation_merge_linestring_gen_z9
    FOR EACH STATEMENT
EXECUTE PROCEDURE transportation.flag_z9();

CREATE CONSTRAINT TRIGGER trigger_refresh_z8
    AFTER INSERT
    ON transportation.updates_z9
    INITIALLY DEFERRED
    FOR EACH ROW
EXECUTE PROCEDURE transportation.refresh_z8();