[postgis-users] overlapping geometries

[Hugues François]

Hello,

 

I’m not sure I understand your whole problem, but I can try to give you the beginning of some answers :

-          The use of ST_Overlaps seems more natural to me to find overlapping geometries (it depends on what you’re looking for, and you may also have look to ST_Intersects but ST_Contains does not return the same kind of results)

-          To compare geometries within a single layer, you can make an auto jointure and a select distinct to remove duplicates. Something like this query may work :

 

SELECT DISTINCT a.* FROM table AS a, table AS b

WHERE a.gid != b.gid  and ST_Overlap(a.geom, b.geom) 

 

HTH

 

Hugues.

 

De : postgis-users-bounces at lists.osgeo.org [mailto:postgis-users-bounces at lists.osgeo.org] De la part de volker.emmel at lwk-rlp.de
Envoyé : jeudi 26 février 2015 14:33
À : postgis-users at lists.osgeo.org
Objet : [postgis-users] overlapping geometries

 

hey list, 

i have the following problem: 

- i have overlapping geometries in one layer in my postgis (8.3) database. 

-> how could i find the overlapping geometries?? 

->i could not divide into two layers... 
-> if i have two layers i could use st_contain, but in one ?? 

- it will be over 6 million geometries.... 

any idea? 

thanks 
vollbtz

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