I happened to see this DBA.StackExchange.com question about killing a big delete, and I really felt for the admin involved:
Four days ago a user ran the command below on a table with 400,000,000 rows. It’s still running and the log file is increasing in size.
Hoo boy. When you kill a query, it’s hard to know when it’s going to finish. WITH STATUSONLY often shows you 0% complete, 0 seconds remaining – no matter how much longer it’ll take. To make matters worse, it doesn’t necessarily match up with how long the query took to execute, either: rolling work