0

Prior to shapefiles and geodatabases, the default ESRI vector data storage format was the coverage. Later iterations of the coverage included the regions concept, whereby (for example) multiple features represented a single region. Hawaii was a classic example, where multiple polygons (islands) were associated with one region (the cluster of islands comprising the State of Hawaii). Specific Arc tools were developed to create, manage and analyze regions-based data. They still exist at the 10.5 level, for example the "Polygon Coverage to Region" tool.

But such tools are specific to the coverage data format, and I don't see the regions concept described in either the shapefile or geodatabase literature. I'm curious how regions are implemented in those more modern data formats. Obviously I'm missing something because Hawaii still exists, even with the slow demise of the coverage!

My specific question is, how is the regions concept - as opposed to individual features - stored, managed and analyzed in shapefiles and geodatabases?

user45726
  • 99
  • 6
  • To the best of my knowledge, the region model died with coverage format. ArcGIS topologies have whatever remains, but its been at least a decade, probably two, since I last used a region. Modern polygons can be multipart, which eliminates the need for regions. – Vince Jul 22 '17 at 18:29
  • Regions (as overlapping polygon toolkit) came out of Esri UK and a paper by David Maguire, Graham Stickler and I about them was presented at UC 92 or 93. They became part of Workstation soon after. Their ability to model multipart polygons was a side benefit to their principal design goal which was to model overlap relationships between polygon features. Technology at the time took MUCH longer to calculate overlap and we decided to pay that price on the way in rather than on the way out. Today the price is so small that paying on the way out is preferred and regions seem no longer necessary. – PolyGeo Jul 22 '17 at 20:42

0 Answers0