单项选择题 Your database supports a DSS workload that involves the execution of complex queries: Currently, the library cache contains the ideal workload for analysis. You want to analyze some of the queries for an application that are cached in the library cache. What must you do to receive recommendations about the efficient use of indexes and materialized views to improve query performance?（）

单项选择题 A new report process containing a complex query is written, with high impact on the database. You wantto collect basic statistics about query, such as the level of parallelism, total database time, and the number of I/O requests. For the database instance STATISTICS_LEVEL, the initialization parameter is set to TYPICAL and theCONTROL_MANAGEMENT_PACK_ACCESS parameter is set to DIAGNOSTIC+TUNING. What should you do to accomplish this task?（）

多项选择题 Your multitenant container database (CDB) contains three pluggable database (PDBs). You find that the control file is damaged. You plan to use RMAN to recover the control file. There are no startup triggers associated with the PDBs. Which three steps should you perform to recover the control file and make the database fully operational?（）