You upgraded from a previous Oracle database version to Oracle Database version to Oracle Database12c. Your database supports a mixed workload. During the day, lots of insert, update, and deleteoperations are performed. At night, Extract, Transform, Load (ETL) and batch reporting jobs are run.
The ETL jobs perform certain database operations using two or more concurrent sessions.After the upgrade, you notice that the performance of ETL jobs has degraded. To ascertain the cause ofperformance degradation, you want to collect basic statistics such as the level of parallelism, totaldatabase time, and the number of I/O requests for the ETL jobs.
How do you accomplish this?（）

You notice a performance change in your production Oracle 12c database. You want to know which change caused this performance difference.
Which method or feature should you use?（）

You are using the flash recovery area (fast recovery area in 11g Release 2) to store backup related files in your database. After regular monitoring of space usage in the Mash recovery area. You realize that the flash recovery area is jetting filled up very fast and it is running out of space. Your database flash recovery area is low on space and you have no more room on disk.
Proactively, which two options could you use to make more space available in the flash recovery？（）

Your database is in ARCHIVELOG mode. You have two online redo log groups, each of which contains one redo member. When you attempt to start the database, you receive the following errors:

Which statement should you use to resolve this issue?（）

You are using a recovery catalog to maintain Recovery Manager (RMAN) backup information for yourproduction database. You have registered your production database and are performing regular backups.
Because of a new requirement you have added a few new tablespaces to your production database and youwant them to be included in backups.Identify two options for completing this task. （）(Choose two.)