[postgis-users] What can i do if polygons are not valid????

[Frank Koormann]

Hi,

* Andreas Laggner <andreas.laggner at fal.de> [070817 11:05]:
> Hi,
> 
> who can tell me something about the error? It occurs with this 
> statements and i guess it is because 122 polygons from ffh are not valid!
> 

You can check this if you limit your processing to the valid, by adding

AND isvalid(t1.the_geom) AND isvalid(t2.the_geom)

to your where clause.

> ffh 27000 rows (122 not valid), spa 1800 rows
> 
> Are there any possibilities to repair ffh or what else can i do????

A usual recommendation to try to fix invalid polygons is 

buffer(the_geom,0.0)

see e.g.
http://postgis.refractions.net/pipermail/postgis-users/2007-May/015766.html

Regards,

        Frank

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