SQL Server的数据库调优顾问是否会修改数据？

I've been trying to increase performance and diagnose deadlocks on a SQL Server 2005 instance. It had been running SQL Server 2000 until a month ago, when an in situ upgrade was done. After the upgrade, we've experienced a number of issues- performance is down and deadlocks are way up. MS suggested we use 2005's Database Engine Tuning Advisor (DTA/DETA). I've been trying to increase performance and di