A long running query was being run on a SQL Server 2005 database which referenced tables on a SQL Server 2000 database. Both instances of SQL Server are running on the same machine. It was only a select query, it did not alter any records. It had run for about 2 hours before it was killed. The process has been in a "KILLED/ROLLBACK" state for over 6 hours.
The CPU Time of the process keeps going up (12827264 as of this message), whilst the Disk IO remains low and constant (8).
We could restart the server and this would probably fix the issue, but I'm keen to know what the cause of this is. What exactly is it rolling back? What is it doing to use up so much CPU? Why might it be taking so long?