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I am trying to run spatial stats (% area of overlap of various datasets) with the World Database of Protected Areas marine shapefile. It's a global collection of marine protected areas, so it's a big polygon file. But I can't seem to do any geoprocessing with it. Clip, Merge, Dissolve... anything I try just runs for hours, never getting anywhere, and I eventually have to cancel it and restart ArcMap.

I've tried manually merging small subsets of polygons (by Edit>Merge), and it appears that particular polygons are causing the problem ("The Merge command could not be completed"), but I have no way I identifying the problem polygons (or why they are problems), and there seems to be many throughout the dataset of >14,000 polygons.

Has anybody worked with the WDPA dataset, and had issues using it in any geoprocessing? How do I make this great dataset useful to me?

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    Try Repair Geometry first on your stubborn data. The other likely possibility is that the intermediate features are too big for a shapefile, this can be more annoying to get around but with persistence you can arrive at a satisfactory result. Note that being worldwide your data is likely to be geographic which will skew your percentages slightly. – Michael Stimson Apr 3 '18 at 4:37
  • Does Repair Geometry typically take a long time? It's been "running" for over 10 mins now, and I don't know if it's doing anything. Re: geographic data: noted. Just need it for descriptive stats, so not a big issue if it's slightly skewed. – wgoodell Apr 3 '18 at 4:56
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    Repair geometry can take a long time, especially if there are a lot of vertices or geometries. – Michael Stimson Apr 3 '18 at 5:22
  • It eventually finished Repair Geometry, but I'm still having same issues with geoprocessing... – wgoodell Apr 3 '18 at 8:00
  • Import the shapefile into a geodatabase and run repair geometry. That should speed things up and increase the size limits. – Tom Apr 3 '18 at 16:08

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