Yes you can but first understand that getting exclusive use of a resource will severly impact concurrency. Ususally, in a SQL Server environment, we don't deal with obtaining exclusive locks on resources. The query processor will exclusively lock a resource to update it, but the lock will be removed at the end of the transaction - which we hope will be very quick.

Check out the sp_lock system stored procedure. It references the system table syslockinfo for info about the locks currently held by all connections.

-Mike