Working with Vector Data –Advanced Recipes - PostGIS - page 198

SELECT (ST_Dump(the_geom)).geom AS the_geom

FROM

polygonized

)

SELECT ST_Multi(ST_Collect(the_geom)) FROM
dumped

;
$$ LANGUAGE SQL;

Now, we can polygonize directly from a set of closed lines and skip the typical in-
termediate step when we use the ST_Polygonize function of having to handle a
GeometryCollection.

See also

• The Translating, scaling, and rotating geometries - advanced recipe