Hello All,
I started working with Esri GIS products around 1995. Being old school, I never create polygon feature classes that allow features to overlap each other. It’s the number one rule of topology (https://resources.arcgis.com/en/help/main/10.2/01mm/pdf/topology_rules_poster.pdf) and the fact that I started with ArcInfo coverages may have something to do with it, also. Has anyone heard of ArcInfo? Around 2006, I was responsible for converting an Autodesk MapGuide Land System to our company Esri platform that included ArcGIS Server. I guess this was around the time SDE connected ArcMap to the SQL Database. I recall when appending overlapping polygons into an existing polygon feature class, the routine would error out. In my old land system (circa 2006), that is still being used today with ArcMap 10.0, adding overlapping polygons to the enterprise geodatabase continues to error out. Somewhere along the way, Esri decided to allow overlapping polygons within a single polygon feature class, but I still don’t. Now, I am reviewing someone else’s data that is part of an ArcGIS Enterprise and I notice around 50% overlap. Most of the overlap are slivers from data that was not cleaned properly, build and clean in ArcInfo. My OCD monster wants to clean these layers for them, but maybe I should let it go as other commitments keep me very busy.
It’s so difficult to explain this concept, so I have the following questions:
- Are overlapping polygons a normal approach when building polygon feature classes today?
- What reasons could I argue for the additional time it would take to clean up all the slivers and gaps?
- What are all the issues that overlapping polygons cause in the future (i.e., spatial query, buffer, distance measurement)?
- What was Esri’s frame of mind when they decided to allow this? Chime in Esri.
- Do I look the other way and hope no issues arise later?
Will sum,
Gerry