[postgis-tickets] [PostGIS] #3587: lwgeom_mindistance2d slows down topology loading

[PostGIS]

#3587: lwgeom_mindistance2d slows down topology loading
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  Reporter:  strk      |      Owner:  strk
      Type:  defect    |     Status:  new
  Priority:  medium    |  Milestone:  PostGIS 2.2.3
 Component:  topology  |    Version:  2.2.x
Resolution:            |   Keywords:  performance
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Comment (by nicklas):

 I have attached a patch that comments out the bbox test and sending to
 faster distance calc.

 I see no difference in timing with that.

 I also think this is very strange.

 I can see 3 possible reasons

 1) Something very smart is happening in GEOS in st_intersects code

 2) We have some very big overhead in our helping functions that for
 instance do very many memory allocations or reallocations, that I don't
 realize when I look at the code.

 3) There is some ugly brain fart in the distance code itself. But since
 1.4 shows the same pattern, I guess that is something we have had for a
 very long time and that I failed to see when I did my changes.


 An interesting thing is that ST_3DIntersects behaves in about the same way
 as the distance functions. That is not strange since it is a wrapper
 around similar code as the 2D distance functions.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/3587#comment:14>
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