topic Re: How does Pro determine which part keeps the original Object ID when splitting a polygon? in ArcGIS Pro Questions

How does Pro determine which part keeps the original Object ID when splitting a polygon?

HollyTorpey_LSA — Tue, 28 Apr 2026 18:43:45 GMT

I need to split polygons in a feature service that is hosted on ArcGIS Online, but I would like to control which of the resulting two polygons retains the original Object ID (because it's used in a filter in a URL parameter for an app link I've already shared). How is it determined which polygon keeps the Object ID? Is it the one on the left or right of the split or something like that?

Re: How does Pro determine which part keeps the original Object ID when splitting a polygon?

ChadKopplin — Tue, 28 Apr 2026 19:43:51 GMT

I believe it would be to the Upper Left and to the left. Back in the ArcInfo PC and Work Station days that is how the ordering went. When you create a new shapefile the items are ordered this way, it starts at the Upper left and goes across the top, the highest feature is numbered first. Then it works it's way through the whole file like that. Thank you.

Re: How does Pro determine which part keeps the original Object ID when splitting a polygon?

HollyTorpey_LSA — Tue, 28 Apr 2026 20:11:54 GMT

Thanks for responding! I've been trying to figure out the pattern and I actually think in Pro it might just be the bigger polygon that keeps the object ID. I've tried splitting in different directions and the larger side seems to always keep the object ID regardless of the direction of the split.

Re: How does Pro determine which part keeps the original Object ID when splitting a polygon?

RyanUthoff — Tue, 28 Apr 2026 20:55:14 GMT

It depends on how you have defined your split model settings in ArcGIS Pro. By default, it uses the Update/Insert model.

In the case of the Update/Insert model, the biggest polygon retains the original ObjectID, while the smaller polygon gets the new ObjectID.

Documentation: https://pro.arcgis.com/en/pro-app/latest/help/data/geodatabases/overview/defining-feature-class-properties.htm#ESRI_SECTION1_C4DE6D7BC03247B2A10F4DC9BFCD768D