The Undo Optimization window displays the script that is used to enact the recommended change. Review the script and either click the Run button to initiate the undo or click Cancel to return to the recommendation you were viewing. The undo script can be copied to clipboard and used at a later time.
Executing the undo script on a recommendation that is not already optimized can harm your SQL Server environment. Before executing the undo script, be sure that the corresponding optimization is performed.
Access the Undo Optimization window
To access the Undo Optimization window, select the row of the recommendation that you previously optimized, and then click Undo Script.