[postgis-tickets] [PostGIS] #4907: Documentation - are SP-GiST indexes really better for overlapping bounding boxes?

[PostGIS]

#4907: Documentation - are SP-GiST indexes really better for overlapping bounding
boxes?
--------------------------+---------------------------
 Reporter:  Laurenz Albe  |      Owner:  pramsey
     Type:  defect        |     Status:  new
 Priority:  medium        |  Milestone:  PostGIS 3.1.2
Component:  postgis       |    Version:  2.5.x
 Keywords:                |
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 [https://postgis.net/docs/manual-
 dev/using_postgis_dbmanagement.html#spgist_indexes The documentation]
 claims that

   The performance tests reveal that SP-GiST indexes are especially
 beneficial when there are many overlapping objects, that is, with so-
 called “spaghetti data”.

 That is counter-intuitive, given that SP-GiST indexes use disjoint
 bounding boxes, and [https://blog.crunchydata.com/blog/the-many-spatial-
 indexes-of-postgis Paul Ramsey's recent blog post] confirms that:

   When there is less overlap, then SPGIST will out-perform GIST.

 Perhaps the documentation should be fixed.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/4907>
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