Which two are true about Oracle Flashback features?

Examine these queries and their output:

After a system crash, an instance restart and an attempted opening of the PDBs result in:

Which two are true?

Which two are true about the Oracle dataabse methodology? (Choose two.)

A user complains about poor database performance.
You want to verify if the user's session has waited for certain types of I/O activity. Which view displays all waits waited on by a session at least once?

Examine these actions:
1. Create a new database for a recovery catalog.
2. Create a tablespace with sufficient space in the catalog database for the recovery catalog.
3. Configure archivelog mode for the catalog database.
4. Create a user to own the recovery catalog schema with quota on the tablespace that will contain the catalog.
5. Grant the recovery_catalog_owner role to the recovery catalog schema owner.
6. Grant the sysbackup privilege to the recovery catalog schema owner.
Which are the minimum actions that must be performed before executing the create catalog command?