[postgis-users] Union fails on 2389 linestrings.

[Maxime van Noppen]

On 07/28/2010 10:15 PM, Jeff Adams wrote:
> OK, I finally have it down to a manageable use case.  Union these 16
> linestrings, you get a topology exception.  Remove any one of them, you
> don't.  What the heck can I do about this?  Simplifying and snapping to
> grid, at any reasonable precision, did not help my larger real data (I
> didn't try with this little test case).
>
> Is there any chance that ST_Union has a bug?  Isn't it supposed to be
> adding the node it complains is missing?

I got it working by simplifying the geometries:

   st_union(st_simplify(geom, 0.001))

if it is of any help.

-- 
Maxime