Saturday, November 20, 2010

WxMap - Speed Increases

After researching an issue in WxMap, I ran some performance tests to see if using a county's database identifier was faster than finding the county by center point.  The current operation, in general, is faster than database access.  If the county appears in the database first, the database method is somewhat faster.

I did some research on my mapping component vendor's website and discovered that using 'rtree' indexing would make the spacial operations faster.  I thought I had already enabled that option.  Upon checking I did find that I enabled that option on each layer.

When I read through several posts, I discovered that rtree indexing should be enabled after adding the layer to the viewer.  I gave that a try and was blown away.  The speed increase is remarkable.  It is well over 100% faster than the old operation.  Users will definately notice the difference if they are alarming the entire United States.

This operation does create an additional file in the Map directory for each map layer.  You will notice a new file for each layer with the extension 'rtree'.  The files are not really large and are created the first time the map program is loaded.

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