[postgis-tickets] [PostGIS] #4182: Unexpected TopologyException during ST_Union aggregate function with valid polygons

[PostGIS]

#4182: Unexpected TopologyException during ST_Union aggregate function with valid
polygons
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  Reporter:  blaggner  |      Owner:  pramsey
      Type:  defect    |     Status:  new
  Priority:  medium    |  Milestone:  PostGIS GEOS
 Component:  postgis   |    Version:  2.3.x
Resolution:            |   Keywords:
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Comment (by mdavis):

 Looking at the LostGIS overlay functions in more detail, it appears that
 they drop back to using MakeValid, and failing that a very small buffer.
 This is certainly one way to deal with issues, and it's nice to have it
 wrapped up in a convenient function.

 Actually using buffer( [A,B], 0 ) is an effective substitute for union(A,
 B).  Do you use that inside your safe_union?

 And that makes me think it might be a useful fix to add to ST_Union
 aggregate, to handle the failures which occur there....  Could be a quick
 short-term fix to help older PG versions.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/4182#comment:12>
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