Database Reference
In-Depth Information
12. Now, you will rebuild the topology using a small tolerance value—1
meter—asanadditionalparametertothe
CreateTopology
function,inor-
dertogetridoftheunnecessaryfaces(thetolerancewillcollapsethevertex
together, eliminating the small polygons). First, drop your topology schema
with the
DropTopology
function, and the topological table with the
DROP
TABLE
command, and rebuild both of them using a topology tolerance of 1
meter, as follows:
postgis_cookbook=# SELECT
DropTopology('hu_topo');
postgis_cookbook=# DROP TABLE
chp03.hu_topo_polygons;
postgis_cookbook=# SELECT
CreateTopology('hu_topo', 3857, 1);
postgis_cookbook=# CREATE TABLE
chp03.hu_topo_polygons(gid serial primary
key, name_1 varchar(75));
postgis_cookbook=# SELECT
AddTopoGeometryColumn('hu_topo','chp03',
'hu_topo_polygons',
