US census national level geodatabase 

 

          Many of national level census data is larger than the ESRI shape file limit (4GB). Census use ESRI geodatabase format instead of shape file.  For example US road has 18 million records (15GB in geojson format, and 3.73GB in geodatabase format). US block has 11 million records (20GB in geojson format, 5.29 GB in geodatabase).  US building footprint has 125 million records in all 50 US states (28.8GB in geojson, about 5 GB in shape file if no 4GB max limit, 3.5 GB in mbtiles).   Mapbox tile (mbtile) was used to compress those huge dataset into relatively smaller one. The compress ratio is 1:10.  Therefor, the US road becomes 1.5GB in mbtile and US block becomes 2GB in mbtile, while keep all the attribute information. Mbtile is visible online with smooth pan, zoom, on map. Geodatabase is not visible unless you have professional gis software installed. Such as  ArcCatalog, ArcMap ( purchase through annual subscription as $$$)

          Through this page, the general public can easily and freely browsing national level census data online otherwise not possible.

          Mbtile remove the need of Arcgis Server, while keep the basic map browsing capability. Since mbtile is a single file, it is easy to download, re-distribute, deploy to anywhere, any mobile device. With Arcgis Server, you have to have a quite expensive computer and pay thousands of $$$ anual subscription to ESRI and hire someone who know how to setup arcgis server, do configuration, performance tuning.    

 

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