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Significant enhancement

Dec 4, 2006 at 7:00 PM
I played around with the dbase and shapefile readers as it was working very slowly for me, like 5-7 seconds for a map rendering at various zoom levels. I now get pretty fast performance with very little change to either class.

My shapefiles / dbf are only 60 mb, not too big. My problems were not on the initialization or spatial index but on subsequent re-draws when you zoom out with more features visible.

I want to start a conversation with some of the developers of sharpmap to find out how to communicate my findings and if they have any comments good or bad about what I have done.

The essence of the changes were to deal with memory streams instead of file streams, read the file 1 time, then never have to deal with disk io again. Disk IO tends to be a bottleneck. The binary reader code still applies.

Jason Apple
Dec 18, 2006 at 5:10 AM
Hi Jason,

I am intrested in the optimization that you have made to the code. I am working on the compact framework version and the map drawing is taking alot of time. I want to check if the solution that you have found will help me.

Please do contact me at

Dec 18, 2006 at 8:32 PM

i'm developping on the PocketPC using .NET Compact Framework, and even when the shapefiles wont be too long, any improvement in performance will be welcome.
Dec 19, 2006 at 2:03 PM
Hi Jason,

I would be interested in the enhancement as well.. I am using files of the size of about 400MB .. your inputs would be really helpful.

Jan 11, 2007 at 6:37 PM

Could you send me any enhancement you developed.
I will look into it.

I think the Shapefile provider is the fastest what SharpMap has.
It is properly indexed?