You use a SQL Server 2005 database named DB1， which is located on a server named SQL1. DB1 is in use 24 hours a day， 7 days a week. A recent copy of DB1 exists on a second server named SQLtest that also runs SQL Server 2005. You detect a high number of full scans on SQL1 and conclude that additional indexes in DB1 are needed. A workload file that is suitable for Database Engine Tuning Advisor （DTA） already exists.   You need to analyze the workload file by using DTA. You must ensure maximum performance on SQL1 during analysis. You must also ensure availability during the implementation of any recommendations suggested by the DTA. What should you do？（）