You work as the database administrator at Domain.com. All servers on the Domain.com network run Windows Server 2003 and all database servers run SQL Server 2005. The Domain.com network contains a database server named Certkiller -DB01. Certkiller -DB01 hosts a database named CK_Sales that stores sales data for the company. The tables in the CK_Sales database are shown in the following database diagram.

You need to optimize the CK_Sales database to support a redesigned stored procedure. You need add a key column to an existing clustered index on the OrderDetails table but you must ensure that the table remains available to users while the index is built.
exhibit What should you do?