[postgis-tickets] [PostGIS] #3753: Gist penalty misbehaves if points are inserted in gridded ordered fashion
PostGIS
trac at osgeo.org
Sun Sep 3 02:30:26 PDT 2017
#3753: Gist penalty misbehaves if points are inserted in gridded ordered fashion
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Reporter: komzpa | Owner: pramsey
Type: defect | Status: new
Priority: blocker | Milestone: PostGIS 2.4.0
Component: postgis | Version: 2.3.x
Resolution: | Keywords:
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Comment (by x4m):
Sorry, I was a bit busy these days.
Replying to [comment:14 robe]:
> So I think all that is left before we can close this ticket is to
perhaps drop the lines you referred to and some retesting to confirm it
improves things.
Previously I observed following
>Before patch selection takes 300 seconds (on my machine) after patch
selection takes 37 seconds... 2D data in 3D
>integer grid for 2D ... index with 43MB size and 109.2 seconds for
select. With patch index size is 56MB and select time 68.2 seconds
This constitute statistically significant performance improvement. Do you
want to restart these tests again?
As to
>drop the lines you referred to
In May, we have made tests with @Komzpa and found no improvement in
dropping the lines. Sorry for not putting that information to the
discussion, we were pinging pictures and gevel images to spot the
difference(induced by dropping the lines) , but found none.
From my point of view, current state is:
1. Best we can achieve by penalty function tuning
2. Contains sufficient improvement over revision 15391
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Ticket URL: <https://trac.osgeo.org/postgis/ticket/3753#comment:16>
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