[postgis-users] Problem cleaning invalid geometries

[L Bogert-OBrien]

Hi,

I am just wondering if there is a way to minimize the extent on which
the cleangeometry() function will act, or rewrite it so that it only
checks out the parts of the multipolygon near the problem area, rather
than having to wait for it to check the validity of all the pieces of
the multipolygon.  Then maybe I wouldn't have to wait days for it to return.

Any ideas?

Thanks,

Loretta
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>I am not sure what you are trying to say with this, but the geometry
>that I am trying to clean is a multipolygon, not a collection.  Yes, it
>is very big and has many points in the multipolygon, since it is the
>Baffin region, but it is not a collection.  ST_geometrytype returns
>multipolygon for it.

There are many possibly kind of invalidity.

If the invalidity is a self-intersect,
of course the ST_MakeValid() could split the polygon on the self-intersect
and produce another multipolygon with one more part.

But if , for example, you multipolygon is invalid because it has a hole of
type Linestring, or because it has two part that are touching along a line.

More probably the st_makevalid could be return a geometrycollection().



-- 
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Andrea Peri
. . . . . . . . .
qwerty ?????o
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