多项选择题 In your production database， you have observed that the database server performance degrades whenever there is a switch between the log groups. On further investigation， you find that the database is running in ARCHIVELOG mode and the archived log files are being written to the same disk that is used to store the redo log members.  Which two actions would you take to improve the performance of the database server？ （）

多项选择题 You want to use the SQL Tuning Advisor to generate recommendations for badly written SQL statements in your development environment.   Which three sources can you select for the advisor to analyze？ （）

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？（）