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List:       postgis-devel
Subject:    Re: [postgis-devel] [PostGIS] #1048: [raster] Coverage version of stats functions should be aggregat
From:       "PostGIS" <trac () osgeo ! org>
Date:       2012-06-29 18:58:50
Message-ID: 058.3fe4e5d37aaafd4fe8dba7c69a281d8a () osgeo ! org
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#1048: [raster] Coverage version of stats functions should be aggregates
-------------------------+--------------------------------------------------
 Reporter:  pracine      |       Owner:  pracine      
     Type:  enhancement  |      Status:  new          
 Priority:  medium       |   Milestone:  PostGIS 2.1.0
Component:  raster       |     Version:  trunk        
 Keywords:               |  
-------------------------+--------------------------------------------------
Changes (by dustymugs):

  * milestone:  PostGIS Future => PostGIS 2.1.0


Comment:

 Just some notes copied for raster/TODO...

 Instead of stats functions using tablename, columnname for a coverage, it
 should be using aggregate functions.  This change isn't too significant
 for
 most of the stats functions.  BUT, the histogram and quantile functions
 will
 need to be rewritten to use 1-pass algorithms that do not require prior
 knowledge of the size of the incoming stream.  The current coverage
 quantile
 function is a 1-pass algorithm but requires prior knowledge of the size of
 the stream.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1048#comment:6>
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