单项选择题 You find that the execution time of reports in your datawarehouse application is significantly high. You suspect the lack of indexes to be the reason for the degradation in performance.  Which advisory component would you refer to， in order to determine the appropriate indexes？（）

单项选择题 You observe that database performance has degraded over a period of time. While investigating the reason， you find that the size of the database buffer cache is not large enough to cache all the needed data blocks.  Which advisory component would you refer to， in order to determine the required size of the database buffer cache？（）

多项选择题 You are performing a block media recovery on the tools01.dbf data file in the SALES database by using RMAN.   Which two statements are correct in this scenario？（）