Oracle Database 12c: Admin, Install and Upgrade Accelerated Quiz Questions and Answers

Identify three valid options for adding a pluggable database (PDB) to an existing multitenant container database (CDB).

Answer :
  • Use the CREATE PLUGGABLE DATABASE statement to create a PDB using the files from the SEED.
  • Use the DBMS_PDB package to clone an existing PDB
  • Use the DBMS_PDB package to plug an Oracle 12c non-CDB database into an existing CDB.

Explanation :

Use the CREATE PLUGGABLE DATABASE statement to create a pluggable database (PDB). This statement enables you to perform the following tasks: * (A) Create a PDB by using the seed as a template Use the create_pdb_from_seed clause to create a PDB by using the seed in the multitenant container database (CDB) as a template. The files associated with the seed are copied to a new location and the copied files are then associated with the new PDB. * (C) Create a PDB by cloning an existing PDB Use the create_pdb_clone clause to create a PDB by copying an existing PDB (the source PDB) and then plugging the copy into the CDB. The files associated with the source PDB are copied to a new location and the copied files are associated with the new PDB. This operation is called cloning a PDB. The source PDB can be plugged in or unplugged. If plugged in, then the source PDB can be in the same CDB or in a remote CDB. If the source PDB is in a remote CDB, then a database link is used to connect to the remote CDB and copy the files. * Create a PDB by plugging an unplugged PDB or a non-CDB into a CDB Use the create_pdb_from_xml clause to plug an unplugged PDB or a non-CDB into a CDB, using an XML metadata file.

Upon starting your ARCHIVELOG mode database, you receive the following error: SQL > startup ORACLE instance started. Total System Global Area 171581440 bytes Fixed Size 1298640 bytes Variable Size 146804528 bytes Database Buffers 20971520 bytes Redo Buffers 2506752 bytes Database mounted. ORA-00313: open failed for members of log group 1 of thread 1 ORA-00312: online log 1 thread 1: '/oracle01/oradata/orcl/redo01.log' ORA-00312: online log 1 thread 1: '/oracle01/oradata/orcl/redo01a.log' You can choose from the following steps: 1. Restore the database data files. 2. Issue the ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP command. 3. Issue the ALTER DATABASE OPEN command. 4. Issue the ALTER DATABASE OPEN RESETLOGS command. 5. Recover the database using point-in-time recovery. 6. Issue the STARTUP MOUNT command to mount the database. 7. Back up the database. Which is the correct order of these steps in this case?

Answer :
  • 6,2,3,7

Explanation :

You should first start the database in mount mode using the STARTUP MOUNT command. You then issue the ALTER DATABASE CLEAR UNARCHIVED LOGFILE command. This will clear the log file if it needs to be archived and recreate the online redo log group. If that command is successful, then you issue the ALTER DATABASE OPEN command. The last step, backing up the database, is very important since your previous backup will not be able to recover the database beyond the point of the cleared redo log sequence number. This is because you have skipped a redo log in the redo log stream.

AUM has been retaining about 15 minutes’ worth of undo. You want to double the retention period but not at the expense of new transactions failing. You decide to alter the system to set the parameter UNDO_RETENTION=18000 . However, AUM still retains only about 15 minutes’ worth of undo. What is the problem? (Choose the best answer.)

Answer :
  • The undo tablespace is not set to autoextend.

Explanation :

AUM will ignore the UNDO_RETENTION parameter if the undo tablespace is not set to autoextend. Option A is incorrect because guaranteeing retention could result in failed transactions, which you specifically want to avoid. Option B is not the best answer because the size of the undo tablespace is not the cause of the issue, but increasing the size of the undo tablespace could increase the amount of undo retained. Option D is wrong because this question is not dealing with the Recycle Bin and because it has no guaranteed retention setting.

Which of the following methods can be used to detect block corruption?

Answer :
  • A) ANALYZE operations
    B) SQL queries that access the potentially corrupt block and dbv
    C) RMAN
    All of the above

Explanation :

Option A is correct because if you attempt to analyze a table or index that has a cor- rupt block, the ANALYZE command will indicate it. Option B is correct because the dbv command (DB Verify utility) is used to verify the data-structure integrity of an offline data file. DB Verify will let you know if the data file fails the integrity check. Option C is correct unless you have used DBMS_REPAIR.SKIP_CORRUPT_BLOCKS to permit queries to skip corrupt blocks. D is correct because the RMAN BACKUP command will detect corruption by default.

Which data dictionary view can be queried to obtain information about the files that belong to locally managed temporary tablespaces?

Answer :
  • DBA_TEMP_FILES

Explanation :

Locally managed temporary tablespaces are created using the CREATE TEMPORARY TABLESPACE command. The data files (temporary files) belonging to these tablespaces are in the DBA_TEMP_FILES view. The EXTENT_MANAGEMENT column of the DBA_TABLESPACES view shows the type of tablespace. The data files belonging to locally managed permanent tablespaces and dictionary-managed (permanent and temporary) tablespaces can be queried from DBA_DATA_FILES. Locally managed temporary tablespaces reduce contention on the data dictionary tables.

Given a complete loss of your database, in what order would you need to perform the following RMAN operations to restore it? a. RESTORE CONTROLFILE b. RESTORE DATABASE c. RESTORE SPFILE d. RECOVER DATABASE e. ALTER DATABASE OPEN f. ALTER DATABASE OPEN RESETLOGS

Answer :
  • c, a, b, d, f

Explanation :

In the event of complete loss of your database, you will need to first restore the database spfile. Once you have restored the database spfile, you will need to restore the database control file. Having restored the database control file, you would restore the database and then recover the database. Finally, since this would be an incomplete recovery (because you lost the entire database, the online redo logs are gone too), you would need to open the database using the ALTER DATABASE OPEN RESETLOGS command.