The ask, figure out why a maker’s Send an HTTP request to SharePoint flow action runs long without returning anything. The action just hangs even though it was running perfectly just a few days ago. Copying and testing the REST API directly in a browser, the maker reported a threshold error message:

The fix, index the columns that the cloud flow is filtering against in SharePoint Online (SPO). Power Automate flows work great when item counts are low but can experience problems as total items near that notorious 5,000 item threshold. The threshold is a common annoyance for anyone working with larger datasets in SPO, but fortunately, it can often be resolved by indexing a few columns. Open the list (or library) settings, then scroll down and select Indexed columns:

From the next screen, select and index any columns that the Power Automate cloud flow needs to query and/ or filter against:

Conclusion:
Power Automate cloud flows benefit when SharePoint Online (SPO) columns are indexed. Indexing does more than improve SPO search.
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