1
2-- Noding a multilinestring
3SELECT 1, ST_AsText(ST_Normalize(ST_UnaryUnion('MULTILINESTRING((0 0, 10 0), (5 -5, 5 5))')) );
4
5-- Unioning a set of polygons (CascadedUnion)
6SELECT 2, ST_AsText(ST_Normalize(ST_UnaryUnion('GEOMETRYCOLLECTION(POLYGON((0 0, 10 0, 10 10, 0 10, 0 0)),POLYGON((5 5, 15 5, 15 15, 5 15, 5 5)))')));
7
8-- Unioning an heterogeneous collection of geometries
9SELECT 3, ST_AsText(ST_Normalize(ST_UnaryUnion('GEOMETRYCOLLECTION(POLYGON((0 0, 10 0, 10 10, 0 10, 0 0)),POLYGON((5 5, 15 5, 15 15, 5 15, 5 5)), MULTIPOINT(5 4, -5 4),LINESTRING(2 -10, 2 20))')));
10
11