[GRASS-dev] [GRASS GIS] #567: v.kernel: suspected i/o bottleneck

[GRASS GIS]

#567: v.kernel: suspected i/o bottleneck
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 Reporter:  dylan        |       Owner:  grass-dev at lists.osgeo.org
     Type:  enhancement  |      Status:  new                      
 Priority:  normal       |   Milestone:  6.5.0                    
Component:  default      |     Version:  svn-develbranch6         
 Keywords:  v.kernel     |    Platform:  Linux                    
      Cpu:  x86-32       |  
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 v.kernel seems to have a disk i/o bottleneck, that starts to cause
 problems with moderately large input vector files. I use this command with
 <3000 point features, with a small region setting: approx 500x500 cells,
 regularly without issue. Trying out a larger dataset, 22k point features
 -- same region geometry, results in a lot of disk activity and very slow
 run-times. I took a peak at the source code, and it looks like there are
 several calls to a spatial index. There was some chatter on the mailing
 list a while back regarding improvement in the way that the spatial index
 is created. I wonder if this would improve v.kernel when working with a
 large number of features.

 The reason that I suspect some kind of I/O issue -- I hear a lot of disk
 trashing while this module is running. Also note that it is using very
 little memory... perhaps some caching would speed things up.

 Some details on the environment:
 {{{
 # region info:
 rows:       632
 cols:       364
 cells:      230048

 # command and arguments
 # file 'soilweb_queries' has approx 22k records
 v.kernel --o in=soilweb_queries out=swq std=50000
 }}}

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Ticket URL: <http://trac.osgeo.org/grass/ticket/567>
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