Add example for hstore with indexes

flex-config/hstore.lua

@@ -0,0 +1,55 @@
+-- This config example file is released into the Public Domain.
+
+-- Use hstore column for storing all tags of nodes and ways. Adds a GIST index
+-- for both tables that allows queries on the geometry *and* the tags.
+--
+-- See https://www.postgresql.org/docs/current/hstore.html#HSTORE-INDEXES
+-- for details.
+--
+-- You need to enable the hstore extension for this to work:
+-- CREATE EXTENSION hstore;
+
+local nodes = osm2pgsql.define_table({
+    name ='nodes',
+    ids = { type = 'node', id_column = 'osm_id' },
+    columns = {
+        { column = 'tags', type = 'hstore' },
+        { column = 'geom', type = 'point' },
+    },
+    indexes = {
+        { column = { 'geom', 'tags' }, method = 'gist' },
+    },
+})
+
+local ways = osm2pgsql.define_table({
+    name ='ways',
+    ids = { type = 'way', id_column = 'osm_id' },
+    columns = {
+        { column = 'tags', type = 'hstore' },
+        { column = 'geom', type = 'geometry' },
+    },
+    indexes = {
+        { column = { 'geom', 'tags' }, method = 'gist' },
+    },
+})
+
+function osm2pgsql.process_node(object)
+    nodes:insert({
+        tags = object.tags,
+        geom = object:as_point(),
+    })
+end
+
+function osm2pgsql.process_way(object)
+    local geom = object:as_polygon()
+
+    if geom:is_null() then
+        geom = object:as_linestring()
+    end
+
+    ways:insert({
+        tags = object.tags,
+        geom = geom,
+    })
+end
+