[postgis-tickets] [PostGIS] #4966: ST_GetFaceGeometry slow with faces with many holes

[PostGIS]

#4966: ST_GetFaceGeometry slow with faces with many holes
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 Reporter:  strk      |      Owner:  strk
     Type:  defect    |     Status:  new
 Priority:  medium    |  Milestone:  PostGIS 3.2.0
Component:  topology  |    Version:  main
 Keywords:            |
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 In the wild I'm facing a face (no pun intended) with 7100 holes (9295
 edges) which takes 1.5 seconds to come out from ST_GetFaceGeometry.

 I've observed that ST_Polygonize(edge.geom) takes 0.5 seconds so it looks
 like ST_BuildArea is making GetFaceGeometry take 3 times as much as
 needed, at the bare minimum.

 I guess we could assume topologies are valid and thus not bother doing
 what ST_BuildArea does to try at building areas, and rely to simply
 building rings and expect a single shell to exist, and consider all the
 others "holes".

 See also #4680 for an idea to implement this internally.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/4966>
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