You upgraded from a previous Oracle database version to Oracle Database version to Oracle Database 12c. Your database supports a mixed workload. During the day, lots of insert, update, and delete operations 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 of performance degradation, you want to collect basic statistics such as the level of parallelism, total database time, and the number of I/O requests for the ETL jobs.
How do you accomplish this?

The HRuser updates the salary of one of the employees in the non-partitioned EMPLOYEEStable, but does not commit the transaction.
Which two types of lock exist in this situation? (Choose two.)

A senior DBA asked you to execute the following command to improve performance:
SQL> ALTER TABLE subscribe log STORAGE (BUFFER_POOL recycle);
You checked the data in the SUBSCRIBE_LOG table and found that it is a large table containing one million rows.
What could be a reason for this recommendation?

Which two statements are true about resumable space allocation? (Choose two.)

Your database is configured in ARCHIVELOG mode.
Examine the RMAN configuration parameters:

Examine the command:
RMAN> BACKUP DATABASE PLUS ARCHIVELOG DELETE INPUT;
Which two are true? (Choose two.)