Which three failures require intervention for recovery? (Choose three.)

In one of your databases, the user HR has the password HRMGR. You want to connect to a database instance whose listener listens on port 1531 by using this statement:
CONNECT HR/HRMGR@orcl
No name server is used.
Which statement is true about ORCL?

Which two statements are true about the results of using the INTERSECT operator in compound queries? (Choose two.)

In your data center, Oracle Managed Files (OMF) is used for all databases.
All tablespaces are smallfile tablespaces.
SALES_Q1 is a permanent user-defined tablespace in the SALES database.
Examine this command which is about to be issued by a DBA logged in to the SALES database:
ALTER TABLESPACE sales_q1 ADD DATAFILE;
Which are two actions, either one of which you could take to ensure that the command executes successfully? (Choose two.)

The SALES_Q1 and USERS tablespaces exist in one of your databases and TEMP is a temporary tablespace.
Segment creation is not deferred.
You execute this command:

Which three statements must be true so that the SALES user can create tables in SALES_Q1? (Choose three.)