多项选择题
A. Statistics collection is not done for the CUSTOMERS table when schema stats are gathered.
B. Statistics collection is not done for the CUSTOMERS table when database stats are gathered.
C. Any existing statistics for the CUSTOMERS table are still available to the optimizer at parse time.
D. Statistics gathered on the CUSTOMERS table when schema stats are gathered are stored as pending statistics.
E. Statistics gathered on the CUSTOMERS table when database stats are gathered are stored as pending statistics.
单项选择题 In a recent Automatic Workload Repository (AWR) report for your database, you notice a high number of buffer busy waits. The database consists of locally managed tablespaces with free list managed segments. On further investigation, you find that buffer busy waits is caused by contention on data blocks. Which option would you consider first to decrease the wait event immediately?（）
单项选择题 The following parameter are set for your Oracle 12c database instance: OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES=FALSE OPTIMIZER_USE_SQL_PLAN_BASELINES=TRUE You want to manage the SQL plan evolution task manually. Examine the following steps: 1. Set the evolve task parameters. 2. Create the evolve task by using the DBMS_SPM.CREATE_EVOLVE_TASK function. 3. Implement the recommendations in the task by using the DBMS_SPM.IMPLEMENT_EVOLVE_TASK function. 4. Execute the evolve task by using the DBMS_SPM.EXECUTE_EVOLVE_TASK function. 5. Report the task outcome by using the DBMS_SPM.REPORT_EVOLVE_TASK function. Identify the correct sequence of steps:（）
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?（）