[postgis-devel] [PostGIS] #1806: Extremely slow and CPU-intensive ST_MakeValid (ST_BuildArea) case

[PostGIS]

#1806: Extremely slow and CPU-intensive ST_MakeValid (ST_BuildArea) case
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  Reporter:  strk     |       Owner:  strk         
      Type:  defect   |      Status:  closed       
  Priority:  high     |   Milestone:  PostGIS 2.0.1
 Component:  postgis  |     Version:  2.0.x        
Resolution:  fixed    |    Keywords:               
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Comment(by hugoledoux):

 @aperi2007: the polygon is actually invalid acc. to the OGC rules because
 the inner ring (grey ring) separate the outer ring into 2 separate
 polygons. The rules of the OGC state, among others, that the inteterior of
 a polygon must be connected. The only solution is to split the polygon
 into 2 polygons (which means that the inner ring disappears, indeed).

 ST_MakeValid does not return per se a POLYGON, but a GEOMETRYCOLLECTION
 which can contain a MULTIPOLYGON, to cope with these situations.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/1806#comment:18>
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