invalid query locator - salesforce

I recently discovered a trick that fixed the issue for our worst-performing dataset.

We had some queries that weren't being used for visualizations, but were only pulled to merge or append into other queries. In the Query Editor, I de-selected "Enable Load". As such, the data for these queries is still added where needed, but the queries don't need to be loaded themselves. A dataset that would never refresh has so far succeeded in about one third of its refreshes after this update.