[mapguide-internals] Raster performance (was Raster provider problems...)

[Jason Birch]

Bob wrote:
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FYI - MapGuide 6.x has single threaded Raster data and DWG data since
those formats were first supported. Yes it is a limitation, but one
users have been living with for years.

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It's probably not a great idea to bring this up right now, but I'd like to talk about raster performance a bit.
 
>From my point of view (at our usage levels per-request speed is more important than concurrent access) raster data was never the limiting factor with 6.5 as long as it was configured properly for LOD at particular view scales.  My main area of optimisation has always been around vector data... making sure that not too much data is attached to requests, limiting secondary joins, generalizing for small scale display, etc.
 
With MGOS architectural changes, I have to worry less about vector performance (SDF is still efficient; though multiple indexes would be nice) and more about raster performance.  I'm sure that a lot of this has to do with smooshing the raster data together with the rendered vector data on the server side...
 
On a recent project, we found that switching overlay generation from PNG to JPG reduced each image from 2MB down to a few hundred K  I wonder if supporting PNG8 would allow for better apparent performance while reducing some of the compression uglyness of JPG.  It seems to for ArcGIS server:
 
http://priour.wordpress.com/tag/arcgis-server/
 
Jason