Flashback is enabled for your multitenant container database (CDB), which contains two pluggable database (PDBs). A local user was accidently dropped from one of the PDBs.
You want to flash back the PDB to the time before the local user was dropped. You connect to the CDB and execute the following commands:
SQL > SHUTDOWN IMMEDIATE
SQL > STARTUP MOUNT
SQL > FLASHBACK DATABASE to TIME "TO_DATE ('08/20/12','MM/DD/YY')";
Examine following commands:
1. ALTER PLUGGABLE DATABASE ALL OPEN;
2. ALTER DATABASE OPEN;
3. ALTER DATABASE OPEN RESETLOGS;
Which command or commands should you execute next to allow updates to the flashed back schema?

To complete the online redefinition procedure, you execute the following command; EXECUTE DBMS_REDEFINITION.FINISH_REDEF_TABLE(`SH', `SALES',
`INT_SALES', 600);
What is the significance of the dml_lock_timeout period of 600 seconds in the preceding command?

Your multitenant container database (CDB) contains three pluggable database (PDBs). You find that the control file is damaged. You plan to use RMAN to recover the control file. There are no startup triggers associated with the PDBs.
Which three steps should you perform to recover the control file and make the database fully operational?

In your database, you want to ensure that idle sessions that are blocking active sessions are automatically terminated after a specified period of time.
How would you accomplish this?

Your database is running In archivelog mode. You back up the control file by executing alter database backup controlfile to trace noresetlogs, whenever you make structural changes to the database. A media failure has damaged all the control files, but the online redo log files are Intact. You issue a shutdown abort.
How would you recover the control file to Its default location?