Extreme wait-time when taking a SQL Server database offline

Question

I\'m trying to perform some offline maintenance (dev database restore from live backup) on my dev database, but the \'Take Offline\' command via SQL Server Management Studio is

Answer 1

There is most likely a connection to the DB from somewhere (a rare example: asynchronous statistic update)

To find connections, use sys.sysprocesses

USE master
SELECT * FROM sys.sysprocesses WHERE dbid = DB_ID('MyDB')

To force disconnections, use ROLLBACK IMMEDIATE

USE master
ALTER DATABASE MyDB SET SINGLE_USER WITH ROLLBACK IMMEDIATE