[postgis-devel] [PostGIS] #851: [raster] Numerous ST_Value query cause the memory to grow indefinitely

[PostGIS]

#851: [raster] Numerous ST_Value query cause the memory to grow indefinitely
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 Reporter:  pracine         |       Owner:  pracine      
     Type:  defect          |      Status:  new          
 Priority:  critical        |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  
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Comment(by pracine):

 No memory growing? Nothing? What if you test on a coverage composed of
 smaller tiles (10x10)? The memory should grow faster and higher.

 This memory growth might be acceptable on one srtm raster but it overflows
 on a coverage composed of many of those.

 This symptom is generalised to most functions. It is worst with ST_Value
 because when iterating over a raster you call it millions of time but the
 same problem would show up with most function if there are millions of
 tiles.

 I am pretty sure this is the same problem Etienne encountered here:

 http://postgis.refractions.net/pipermail/postgis-
 devel/2011-January/011505.html

 The test I did was to simplify RASTER_getPixelValue to the point where it
 just returns a constant, no ctx, nada and in this case there is no general
 memory growth. Every function should release any memory allocated and the
 memory use should be almost constant without growing constantly.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/851#comment:11>
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