1Z0-062 Exam - Oracle Database 12c: Installation and Administration

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Q1. You use a recovery catalog for maintaining your database backups. 

You execute the following command: $rman TARGET / CATALOG rman / cat@catdb RMAN > BACKUP VALIDATE DATABASE ARCHIVELOG ALL; 

Which two statements are true? 

A. Corrupted blocks, if any, are repaired. 

B. Checks are performed for physical corruptions. 

C. Checks are performed for logical corruptions. 

D. Checks are performed to confirm whether all database files exist in correct locations 

E. Backup sets containing both data files and archive logs are created. 

Answer: B,D 

Explanation: B (not C): You can validate that all database files and archived redo logs can be backed up by running a command as follows: 

RMAN> BACKUP VALIDATE DATABASE ARCHIVELOG ALL; 

This form of the command would check for physical corruption. To check for logical corruption, 

RMAN> BACKUP VALIDATE CHECK LOGICAL DATABASE ARCHIVELOG ALL; 

D: You can use the VALIDATE keyword of the BACKUP command to do the following: 

Check datafiles for physical and logical corruption 

Confirm that all database files exist and are in the correct locations. 

Note: You can use the VALIDATE option of the BACKUP command to verify that database files exist and are in the correct locations (D), and have no physical or logical corruptions that would prevent RMAN from creating backups of them. When performing a BACKUP...VALIDATE, RMAN reads the files to be backed up in their entirety, as it would during a real backup. It does not, however, actually produce any backup sets or image copies (Not A, not E). 

Q2. Identify two situations in which the alert log file is updated. 

A. Running a query on a table returns ORA-600: Internal Error. 

B. Inserting a value into a table returns ORA-01722: invalid number. 

C. Creating a table returns ORA-00955: name us already in used by an existing objects. 

D. Inserting a value into a table returns ORA-00001: unique constraint (SYS.OK_TECHP) violated. 

E. Rebuilding an index using ALTER INDEX . . . REBUILD fails with an ORA-01578: ORACLE data block corrupted (file # 14, block # 50) error. 

Answer: A,E 

Explanation: The alert log is a chronological log of messages and errors, and includes the following items: 

*All internal errors (ORA-600), block corruption errors (ORA-1578), and deadlock errors (ORA-60) that occur 

* Administrative operations, such as CREATE, ALTER, and DROP statements and STARTUP, SHUTDOWN, and ARCHIVELOG statements 

* Messages and errors relating to the functions of shared server and dispatcher processes 

* Errors occurring during the automatic refresh of a materialized view 

* The values of all initialization parameters that had nondefault values at the time the database and instance start 

Note: 

* The alert log file (also referred to as the ALERT.LOG) is a chronological log of messages and errors written out by an Oracle Database. Typical messages found in this file is: database startup, shutdown, log switches, space errors, etc. This file should constantly be monitored to detect unexpected messages and corruptions. 

Q3. You enabled an audit policy by issuing the following statements: 

SQL> AUDIT POLICY ORA_DATABASE_PARAMETER BY SCOTT; 

SQL> AUDIT POLICY ORA_DATABASE_PARAMETER BY SYS, SYSTEM; 

For which database users and for which executions is the audit policy now active? Select two. 

A. SYS, SYSTEM 

B. SCOTT 

C. Only for successful executions 

D. Only for failed executions 

E. Both successful and failed executions 

Answer: A,E 

Explanation: * The ORA_DATABASE_PARAMETER policy audits commonly used Oracle Database parameter settings. By default, this policy is not enabled. 

Q4. You have installed two 64G flash devices to support the Database Smart Flash Cache feature on your database server that is running on Oracle Linux. 

You have set the DB_SMART_FLASH_FILE parameter: 

DB_FLASH_CACHE_FILE= ‘/dev/flash_device_1 ‘,’ /dev/flash_device_2’ 

How should the DB_FLASH_CACHE_SIZE be configured to use both devices? 

A. Set DB_FLASH_CACHE_ZISE = 64G. 

B. Set DB_FLASH_CACHE_ZISE = 64G, 64G 

C. Set DB_FLASH_CACHE_ZISE = 128G. 

D. DB_FLASH_CACHE_SIZE is automatically configured by the instance at startup. 

Answer:

Explanation: * Smart Flash Cache concept is not new in Oracle 12C - DB Smart Flash Cache in Oracle 11g. 

In this release Oracle has made changes related to both initialization parameters used by DB Smart Flash cache. Now you can define many files|devices and its sizes for “Database Smart Flash Cache” area. In previous releases only one file|device could be defined. 

DB_FLASH_CACHE_FILE = /dev/sda, /dev/sdb, /dev/sdc 

DB_FLASH_CACHE_SIZE = 32G, 32G, 64G 

So above settings defines 3 devices which will be in use by “DB Smart Flash Cache” 

/dev/sda – size 32G /dev/sdb – size 32G /dev/sdc – size 64G New view V$FLASHFILESTAT – it’s used to determine the cumulative latency and read counts of each file|device and compute the average latency 

Q5. Which three statements are true about Flashback Database? 

A. Flashback logs are written sequentially, and are archived. 

B. Flashback Database uses a restored control file to recover a database. 

C. The Oracle database automatically creates, deletes, and resides flashback logs in the Fast Recovery Area. 

D. Flashback Database can recover a database to the state that it was in before a reset logs operation. 

E. Flashback Database can recover a data file that was dropped during the span of time of the flashback. 

F. Flashback logs are used to restore to the blocks' before images, and then the redo data may be used to roll forward to the desired flashback time. 

Answer: B,C,F 

Explanation: * Flashback Database uses its own logging mechanism, creating flashback logs and storing them in the fast recovery area (C). You can only use Flashback Database if flashback logs are available. To take advantage of this feature, you must set up your database in advance to create flashback logs. 

* To enable Flashback Database, you configure a fast recovery area and set a flashback retention target. This retention target specifies how far back you can rewind a database with Flashback Database. 

From that time onwards, at regular intervals, the database copies images of each altered block in every data file into the flashback logs. These block images can later be reused to reconstruct the data file contents for any moment at which logs were captured. (F) 

Incorrect: Not E: You cannot use Flashback Database alone to retrieve a dropped data file. If you flash back a database to a time when a dropped data file existed in the database, only the data file entry is added to the control file. You can only recover the dropped data file by using RMAN to fully restore and recover the data file. 

Reference: Oracle Database Backup and Recovery User's Guide 12c R 

Q6. You performed an incremental level 0 backup of a database: 

RMAN > BACKUP INCREMENTAL LEVEL 0 DATABASE; 

To enable block change tracking after the incremental level 0 backup, you issued this 

command: 

SQL > ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE 

‘ /mydir/rman_change_track.f’; 

To perform an incremental level 1 cumulative backup, you issued this command: 

RMAN> BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE; 

Which three statements are true? 

A. Backup change tracking will sometimes reduce I/O performed during cumulative incremental backups. 

B. The change tracking file must always be backed up when you perform a full database backup. 

C. Block change tracking will always reduce I/O performed during cumulative incremental backups. 

D. More than one database block may be read by an incremental backup for a change made to a single block. 

E. The incremental level 1 backup that immediately follows the enabling of block change tracking will not read the change tracking file to discover changed blocks. 

Answer: A,D,E 

Explanation: A: In a cumulative level 1 backup, RMAN backs up all the blocks used since the most recent level 0 incremental backup. 

E:.Oracle Block Change Tracking Once enabled; this new 10g feature records the modified since last backup and stores the log of it in a block change tracking file using the CTW (Change Tracking Writer) process. During backups RMAN uses the log file to identify the specific blocks that must be backed up. This improves RMAN's performance as it does not have to scan whole datafiles to detect changed blocks. Logging of changed blocks is performed by the CTRW process which is also responsible for writing data to the block change tracking file. 

Note: 

* An incremental level 0 backup backs up all blocks that have ever been in use in this database. 

Q7. Which statement is true about the Log Writer process? 

A. It writes when it receives a signal from the checkpoint process (CKPT). 

B. It writes concurrently to all members of multiplexed redo log groups. 

C. It writes after the Database Writer process writes dirty buffers to disk. 

D. It writes when a user commits a transaction. 

Answer:

Reference: http://docs.oracle.com/cd/B19306_01/server.102/b14220/process.htm (see log writer process (LGWR)) 

Q8. Which statement is true regarding the startup of a database instance? 

A. The instance does not start up normally and requires manual media recovery after a shutdown using the abort option. 

B. Uncommitted transactions are rolled back during the startup of the database instance after a shutdown using the immediate option. 

C. There is no difference in the underlying mechanics of the startup whether the database is shut down by using the immediate option or the abort option. 

D. Media recovery is required when the database is shut down by using either the immediate option or the abort option. 

E. Instance recovery is not required if the database instance was shut down by using SHUTDOWN IMMEDIATE. 

Answer:

Reference: http://docs.oracle.com/cd/A87860_01/doc/server.817/a76956/start.htm 

Q9. Examine the memory-related parameters set in the SPFILE of an Oracle database: 

memory_max_target—6G memory_target=5G pga_aggregate_target=500M sga_max_size=0 sga_target=0 

Which statement is true? 

A. Only SGA components are sized automatically-

B. Memory is dynamically re-allocated between the SGA and PGA as needed. 

C. The size of the PGA cannot grow automatically beyond 500 MB. 

D. The value of the MEMORY_TARGET parameter cannot be changed dynamically. 

Answer:

Q10. Your multitenant container database, CDB1, is running in ARCHIVELOG mode and has two pluggable databases, HR_PDB and ACCOUNTS_PDB. An RMAN backup exists for the database. 

You issue the command to open ACCOUNTS_PDB and find that the USERDATA.DBF data file for the default permanent tablespace USERDATA belonging to ACCOUNTS_PDB is corrupted. 

What should you do before executing the commands to restore and recover the data file in ACCOUNTS_PDB? 

A. Place CDB1 in the mount stage and then the USERDATA tablespace offline in ACCOUNTS_PDB. 

B. Place CDB1 in the mount stage and issue the ALTER PLUGGABLE DATABASE accounts_pdb CLOSE IMMEDIATE command. 

C. Issue the ALTER PLUGGABLE DATABASE accounts_pdb RESTRICTED command. 

D. Take the USERDATA tablespace offline in ACCOUNTS_PDB. 

Answer:

Explanation: * You can take an online tablespace offline so that it is temporarily unavailable for general use. The rest of the database remains open and available for users to access data. Conversely, you can bring an offline tablespace online to make the schema objects within the tablespace available to database users. The database must be open to alter the availability of a tablespace.