The report runs for a long time with no data to retrieve message. At DB level the query runs for hours(2-3 and more sometimes)without any output or error . The same report refreshed fine last month and no changes were made in between, so suspect the data being fetched is comparatively higher this month. But the SQL at DB level should work(and yes we got the DB performance verified and found nothing suspicious)?
We scheduled the same report and there was no data seen after it ran for 3- 5 minutes, instance was successful.
The query has UNION operator, not sure if that is the cause of the concern?