[postgis-users] How to eliminate small gaps produced by ST_union?

[Alexandre Neto]

I'm trying to Aggregate\Dissolve a set of adjacent, but not touching
polygons in Postgis. The geometries were created editing the Postgis table
in QGIS created, with snapping and avoid overlap in the layer.

I used ST_Union like this:

SELECT ST_Union(the_geom)
FROM table;

Small gaps similar to lines appear in the result. This happens when the
adjacent polygons do not share the exact same vertices.

[image: Inline image 2]
Is there a way to eliminate this "gaps" or "small angles" within Postgis?

I know that v.clean in GRASS can eliminate small angles, and correct
topology, but that would mean I needed to copy the features to GRASS,
correct them and copy it back to Postgis.

Thanks in advance,

Alexandre Neto
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