Please help me understand the following
====
SELECT
ST_Nrings(the_geom) nr,
ST_NumInteriorRings(the_geom) nir,
ST_AsText(the_geom) WKT
FROM table
WHERE objectid = 280;
nr nir WKT
-- --- ----------------------------------------------------------------
4 3 "MULTIPOLYGON(((..),(..),(..),(..)))"
====
Looking at the above, I am assuming the first (..) is the exterior ring, and
the remaning three (..) are the 3 interior rings. However,
====
SELECT ST_ExteriorRing(the_geom) er
FROM table
WHERE objectid = 280;
ERROR: ExteriorRing: geom is not a polygon
====
So, what is going on? Of course, the docs say that ST_ExteriorRing doesn't work
on a MULTIPOLYGON. So, is the above only an implementation anomaly, and I can
treat the first ring as an exterior ring? Or, is it really something else?
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