Support more region utils, such as convex hull

script/sql/create/32.region.sql

@@ -5,3 +5,27 @@ create table region
 );
 
 create index region_gist on region using gist(boundary);
+
+
+create table temp_region
+(
+  id text primary key
+, boundary geometry not null unique
+);
+
+create index temp_region_gist on temp_region using gist(boundary);
+
+
+create table temp_node
+(
+  node varchar(32) primary key references _node(id)
+);
+
+
+create table temp_vd_topology
+(
+  id serial
+, source integer
+, target integer
+, cost numeric
+);

script/sql/drop/32.region.sql

@@ -1,3 +1,11 @@
+drop table if exists temp_vd_topology;
+
+drop table if exists temp_node;
+
+drop index if exists temp_region_gist;
+
+drop table if exists temp_region;
+
 drop index if exists region_gist;
 
 drop table if exists region;