单项选择题 While tuning a SQL statement, the SQL Tuning Advisor finds an existing SQL profile for the statement that has stale statistics available. What would the optimizer do in this situation?（）

单项选择题 You need to restore your database back to 9/30/2008 at 18：00. In what order would you run the following commands to compete this task？（）   a. restore controlfile until time `09/30/2008：18：00：00’ b. restore database until time `09/30/2008：18：00：00’  c. restore spfile until time `09/30/2008：18：00：00’ d. recover database until time `09/30/2008：18：00：00’ e. alter database open resetlogs f. alter database open

多项选择题 Which two statements about the SQL Management Base (SMB) are true? （）(Choose two.)