[mapguide-trac] #1999: MgCooker: more than 90% of time wasted to build blank tiles

[MapGuide Open Source]

#1999: MgCooker: more than 90% of time wasted to build blank tiles
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   Reporter:  znarf1965  |       Owner:  jng                   
       Type:  defect     |      Status:  new                   
   Priority:  low        |   Milestone:  Maestro-5.0           
  Component:  Maestro    |     Version:  2.1.0                 
   Severity:  critical   |    Keywords:  Maestro MgCooker Tiles
External_id:             |  
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 Dear Sirs,

 Tile system is a great tool, fundamental, in some cases. The big problem
 is the time it takes to pre generate tiles. The performances in many cases
 are so bad that it is nearly impossible to generate tiles. The
 performances problem are mainly related to the huge amount of blank and
 useless tiles it creates.

 I’ve made a very simple example regarding a very small town and very
 simple data. In this case and for scales 1:35000, 1:5000 and 1:2500 the
 generated tiles are more than 90% blank. If I try to tile closer scales
 (1:1000 or 1:200) the percentage get even worse.

 I’ve made many tests on Mapguide 2.4 32bits (Windows 7) and 64 bits
 (Windows Server 2008) changing parameters and the best performances I get
 checking “Use official methods” and leaving “meters pr unit” = 1.

 Nothing changes if I try to limit bounds by overriding. The parameters are
 not used and the estimation on the amount of tiles remains the same.

 I've attached an mgp with a readme that explains my steps to generate the
 problem as I have on my environment.

 Best regards

 Francesco

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Ticket URL: <http://trac.osgeo.org/mapguide/ticket/1999>
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