1z0-053 Exams Study Guides

By Author: Kristi B. McLeod
Total Articles: 155
Comment this article

Question: 1

The INV_HISTORY table is created using the command:

The following data has been inserted into the INV_HISTORY table:

You would like to store the data belonging to the year 2006 in a single partition and issue the command:
SQL> ALTER TABLE inv_history
MERGE PARTITIONS
FOR(TO_DATE('15-feb-2006','dd-mon-yyyy')),
FOR(TO_DATE('15-apr-2006'))
INTO PARTITION sys_py;
What would be the outcome of this command?

A. It executes successfully, and the transition point is set to '1-apr-2006'.
B. It executes successfully, and the transition point is set to '15-apr-2006'.
C. It produces an error because the partitions specified for merging are not adjacent.
D. It produces an error because the date values specified in the merge do not match the date values stored in the table.

Answer: C

Question: 2

You want to perform the following operations for the DATA ASM disk group:
• Verify the consistency of the disk.
• Cross-check all the file extent maps and allocation tables for consistency.
...
... • Check whether the alias metadata directory and file directory are linked correctly.
• Check that ASM metadata directories do not have unreachable allocated blocks.
Which command accomplishes these tasks?

A. ALTER DISKGROUP data CHECK;
B. ALTER DISKGROUP data CHECK DISK;
C. ALTER DISKGROUP data CHECK FILE;
D. ALTER DISKGROUP data CHECK DISK IN FAILURE GROUP 1;

Answer: A

Explanation:
Syntax: ALTER DISKGROUP CHECK [REPAIR | NOREPAIR];
The check_diskgroup_clause lets you verify the internal consistency of Oracle ASM disk group metadata. The disk group must be mounted. Oracle ASM displays summary errors and writes the details of the detected errors in the alert log.
The CHECK keyword performs the following operations:
• Checks the consistency of the disk.
• Cross checks all the file extent maps and allocation tables for consistently.
• Checks that the alias metadata directory and file directory are linked correctly.
• Checks that the alias directory tree is linked correctly.
• Checks that Oracle ASM metadata directories do not have unreachable allocated blocks.
Refer to here

Question: 3

Which two statements are true regarding the functionality of the remap command in ASMCMD? (Choose two.)

A. It repairs blocks that have read disk I/O errors.
B. It checks whether the alias metadata directory and the file directory are linked correctly.
C. It repairs blocks by always reading them from the mirror copy and writing them to the original location.
D. It reads the blocks from a good copy of an ASM mirror and rewrites them to an alternate location on disk if the blocks on the original location cannot be read properly.

Answer: A, D

Explanation:
Reference from the Oracle document release v11.1 at here:
Repairs a range of physical blocks on a disk. The remap command only repairs blocks that have read disk I/O errors. It does not repair blocks that contain corrupted contents, whether or not those blocks can be read. The command assumes a physical block size of 512 bytes and supports all allocation unit sizes (1 to 64 MB).
Reference from the Oracle document release v11.2 at here:
The remap command marks a range of blocks as unusable on the disk and relocates any data allocated in that range.

Question: 4

What is the advantage of setting the ASM-preferred mirror read for the stretch cluster configuration?

A. It improves resync operations.
B. This feature enables much faster file opens.
C. It improves performance as fewer extent pointers are needed in the shared pool.
D. It improves performance by reading from a copy of an extent closest to the node.

Answer: D

Explanation:
Preferred Read Failure Groups
When you configure Oracle ASM failure groups, it might be more efficient for a node to read from an extent that is closest to the node, even if that extent is a secondary extent. In other words, you can configure Oracle ASM to read from a secondary extent if that extent is closer to the node instead of Oracle ASM reading from the primary copy which might be farther from the node. Using the preferred read failure groups feature is most useful in extended clusters.

Question: 5

Examine the following command:
ALTER DISKGROUP data MOUNT FORCE;
In which scenario can you use the above command to mount the disk group?

A. when ASM disk goes offline
B. when one or more ASM files are dropped
C. when some disks in a disk group are offline
D. when some disks in a failure group for a disk group are rebalancing

Answer: C

Explanation:
In the FORCE mode, Oracle ASM attempts to mount the disk group even if it cannot discover all of the devices that belong to the disk group. This setting is useful if some of the disks in a normal or high redundancy disk group became unavailable while the disk group was dismounted. When MOUNT FORCE succeeds, Oracle
ASM takes the missing disks offline.
If Oracle ASM discovers all of the disks in the disk group, then MOUNT FORCE fails. Therefore, use the MOUNT FORCE setting only if some disks are unavailable. Otherwise, use NOFORCE.
In normal- and high-redundancy disk groups, disks from one failure group can be unavailable and MOUNT FORCE will succeed. Also in high-redundancy disk groups, two disks in two different failure groups can be unavailable and MOUNT FORCE will succeed. Any other combination of unavailable disks causes the operation to fail, because Oracle ASM cannot guarantee that a valid copy of all user data or metadata exists on the available disks.
Refer to here

Question: 6

Which background process of a database instance, using Automatic Storage Management (ASM), connects as a foreground process into the ASM instance?

A. ASMB
B. PMON
C. RBAL
D. SMON

Answer: A

Explanation:
ASMB (ASM Background Process): Communicates with the ASM instance, managing storage and providing statistics, runs in ASM instances when the ASMCMD cp command runs or when the database instance first starts if the server parameter file is stored in ASM. ASMB also runs with Oracle Cluster Registry on ASM.
RBAL (ASM Rebalance Master Process): In an ASM instance, it coordinates rebalance activity for disk groups. In a database instances, it manages ASM disk groups.
PMON (Process Monitor): Monitors the other background processes and performs process recovery when a server or dispatcher process terminates abnormally.
SMON (System Monitor Process): Performs critical tasks such as instance recovery and dead transaction recovery, and maintenance tasks such as temporary space reclamation, data dictionary cleanup, and undo tablespace management

Question: 7

Immediately after adding a new disk to or removing an existing disk from an ASM instance, you find that the performance of the database goes down initially until the time the addition or removal process is completed, and then gradually becomes normal.
Which two activities would you perform to maintain a consistent performance of the database while adding or removing disks? (Choose two.)

A. Define the POWER option while adding or removing the disks.
B. Increase the number of ARB processes by setting up a higher value for ASM_POWER_LIMIT.
C. Increase the number of DBWR processes by setting up a higher value for DB_WRITER_PROCESSES.
D. Increase the number of slave database writer processes by setting up a higher value for DBWR_IO_SLAVES.

Answer: A, B

Explanation:
ARBn (ASM Rebalance Process): Rebalances data extents within an ASM disk group, possible processes are ARB0-ARB9 and ARBA.
ALTER DISKGROUP..POWER clause, specify a value from 0 to 11, where 0 stops the rebalance operation and 11 permits Oracle ASM to execute the rebalance as fast as possible. The value you specify in the POWER clause defaults to the value of the ASM_POWER_LIMIT initialization parameter. If you omit the POWER clause, then Oracle ASM executes both automatic and specified rebalance operations at the power determined by the value of the ASM_POWER_LIMIT initialization parameter.
Note:
Beginning with Oracle Database 11g Release 2 (11.2.0.2), if the COMPATIBLE.ASM disk group attribute is set to 11.2.0.2 or higher, then you can specify a value from 0 to 1024 in the POWER clause.

Question: 8

Identify three key features of ASM. (Choose three.)

A. file striping
B. allocation unit mirroring
C. automatic disk rebalancing
D. automatic file size increment
E. automatic undo management

Answer: A, B, C

Question: 9

You have three production databases, HRDB, FINDB, and ORGDB, that use the same ASM instance. At the end of the day, while all three production database instances are running, you execute the following command on the ASM instance:
SQL> shutdown immediate;
What is the result of executing this command?

A. The ASM instance is shut down, but the other instances are still running.
B. It results in an error because other database instances are connected to it.
C. All the instances, including the ASM instance, are shut down in the IMMEDIATE mode.
D. HRDB, FINDB, and ORGDB instances are shut down in the ABORT mode and the ASM instance is shut down in the IMMEDIATE mode.

Answer: B

Question: 10

You are managing an ASM instance. You previously issued the following statements:
ALTER DISKGROUP dg1 DROP DISK disk2;
ALTER DISKGROUP dg1 DROP DISK disk3;
ALTER DISKGROUP dg1 DROP DISK disk5;
You want to cancel the disk drops that are pending for the DG1 disk group.
Which statement should you issue?

A. ALTER DISKGROUP dg1 UNDROP disk2, disk3, disk5;
B. ALTER DISKGROUP dg1 UNDROP;
C. ALTER DISKGROUP dg1 UNDROP DISKS;
D. You cannot cancel the pending disk drops.

Answer: C

Explanation:

Use this clause to cancel the drop of disks from the disk group. You can cancel the pending drop of all the disks in one or more disk groups (by specifying diskgroup_name) or of all the disks in all disk groups (by specifying ALL).
This clause is not relevant for disks that have already been completely dropped from the disk group or for disk groups that have been completely dropped. This clause results in a long-running operation. You can see the status of the operation by querying the V$ASM_OPERATION dynamic performance view.

Question: 11

What is the effect of increasing the value of the ASM_POWER_LIMIT parameter?

A. The number of DBWR processes increases
B. The number of ASMB processes increases
C. The number of DBWR_TO_SLAVES increases
D. The rebalancing operation in an ASM instance completes more quickly, but can result in higher I/O overhead

Answer: D

Question: 12

ASM supports all but which of the following file types? (Choose all that apply.)

A. Database files
B. SPFILEs
C. Redo-log files
D. Archived log files
E. RMAN backup sets
F. Password files
G. init.ora files

Answer: F, G

Explanation:
What Types of Files Does Oracle ASM Support?

Question: 13

After executing the command
ALTER DISKGROUP diskgroup2 DROP DISK dg2a;
You issue the following command from the ASM instance:
SELECT group_number, COUNT(*) FROM v$asm_operation;
What is the implication if the query against V$ASM_OPERATION returns zero rows?

A. The drop disk operation is still proceeding and you cannot yet run the undrop disks operation.
B. The drop disk operation is complete and you can run the undrop disks command if needed.
C. The drop disk operation is complete and you cannot run the undrop disks command.
D. The query will fail since there is not a V$ASM_OPERATION view available in an ASM instance.
E. None of the above is true.

Answer: C

Explanation:
Once the DROP DISK operation is completed, you CANNOT run the UNDROP DISKS command any more.

Question: 14

What is the net effect of the following command?
alter diskgroup dgroup1 drop disk abc;

A. The disk ABC will be dropped from the disk group. Since you did not issue a rebalance command, the data on that disk will be lost.
B. The command will raise an error indicating that you need to rebalance the disk group to remove the data from that disk prior to dropping the disk.
C. The disk group will be automatically rebalanced during the drop operation. Once the rebalancing is complete, the disk will be dropped.
D. This command will fail because you cannot drop a specific disk in an ASM disk group.
E. The disk drop command will be suspended for a predetermined amount of time, waiting for you to also issue an alter diskgroup rebalance command. Once you have issued the rebalance command, ASM will proceed to rebalance the disk group and then drop the disk.

Answer: C

Question: 15

Which of the following is not a configurable attribute for an individual disk group?

A. AU_SIZE
B. COMPATIBLE.RDBMS
C. COMPATIBLE.ASM
D. DISK_REPAIR_TIME
E. DG_DROP_TIME

Answer: E

Explanation:
DG_DROP_TIME is an invalid DG attribute.
Disk Group Attributes
The DISK_REPAIR_TIME disk group attribute specifies how long a disk remains offline before ASM drops the disk.
The COMPATIBLE.ASM attribute determines the minimum software version for an ASM instance that uses the disk group.
The COMPATIBLE.RDBMS attribute determines the minimum COMPATIBLE database initialization parameter setting for any database instance that uses the disk group.
The AU_SIZE attribute determines the allocation unit size of the disk group. The values can be 1, 2, 4, 8, 16, 32, and 64 MB.

Question: 16

Your organization decided to upgrade the existing Oracle 10g database to Oracle 11g database in a multiprocessor environment.
At the end of the upgrade, you observe that the DBA executes the following script:
SQL> @utlrp.sql
What is the significance of executing this script?

A. It performs parallel recompilation of only the stored PL/SQL code.
B. It performs sequential recompilation of only the stored PL/SQL code.
C. It performs parallel recompilation of any stored PL/SQL as well as Java code.
D. It performs sequential recompilation of any stored PL/SQL as well as Java code.

Answer: C

Explanation:
Recompile invalid objects with utlrp.sql

Question: 17

You are maintaining the SALES database. You have added a new disk to a disk group. Automatic Storage Management performs the rebalancing activity. You want to speed up the rebalancing activity.
Which parameter should you specify to control the speed of the rebalancing activity?

A. ASM_POWER_LIMIT
B. ASM_DISKSTRING
C. ASM_DISKGROUPS
D. INSTANCE_TYPE

Answer: A

Question: 18

What are the recommendations for Oracle Database 11g installation to make it Optimal Flexible Architecture (OFA)-compliant? (Choose all that apply.)

A. ORACLE_BASE should be set explicitly.
B. An Oracle base should have only one Oracle home created in it.
C. Flash recovery area and data file location should be on separate disks.
D. Flash recovery area and data file location should be created under Oracle base in a non-Automatic Storage Management (ASM) setup.

Answer: A, C, D

Question: 19

In your database, the LDAP_DIRECTORY_SYSAUTH initialization parameter has been set to YES and the users who need to access the database as DBAs have been granted SYSDBA enterprise role in Oracle Internet Directory (OID). SSL and the password file have been configured. A user SCOTT with the SYSDBA privilege tries to connect to the database instance from a remote machine using the command:
$ SQLPLUS scott/tiger@DB01 AS SYSDBA
Which DB01 is the net service name.
Which authentication method would be used first?

A. authentication by password file
B. authentication by using certificates over SSL
C. authentication by using the Oracle Internet Directory
D. authentication by using the local OS of the database server

Answer: A

Question: 20

You are managing an Oracle Database 11g database with the ASM storage. The database is having big file tablespaces. You want files to open faster and less memory to be used in the shared pool to manage the extent maps.
What configuration would you effect to achieve your objective? (Choose all that apply.)

A. Set the ASM compatibility attribute for the ASM disk group to 11.1.0.
B. Set the RDBMS compatibility attribute for the ASM disk group to 11.1.0.
C. Set the COMPATIBLE initialization parameter for the ASM instance to 11.1.0.
D. Set the COMPATIBLE initialization parameter for the database instance to 11.1.0.

Answer: A, D

Question: 21

Which two statements are true regarding an Automatic Storage Management (ASM) instance? (Choose two.)

A. An ASM instance mounts an ASM control file
B. An ASM instance uses the ASMB process for rebalancing of disks within a disk group
C. Automatic Memory Management is enabled in an ASM instance even when the MEMORY_TARGET parameter is not set explicitly
D. An RDBMS instance gets connected to an ASM instance using ASMB as a foreground process when the database instance is started

Answer: C, D

Question: 22

Users are connected to a database instance that is using Automatic Storage Management (ASM). The DBA executes the command as follows to shut down the ASM instance:
SQL> SHUTDOWN IMMEDIATE;
What happens to the database instance?

A. It shuts down long with the ASM instance.
B. It is aborted and the ASM instance shuts down normally.
C. It stays open and SHUTDOWN command for the ASM instance fails.
D. It shuts down only after all pending transactions are completed and the ASM instance waits for this before shutting down.

Answer: C

Explanation:
IMMEDIATE or TRANSACTIONAL Clause (link)
Oracle ASM waits for any in-progress SQL to complete before performing an orderly dismount of all of the disk groups and shutting down the Oracle ASM instance. Oracle ASM does not wait for users currently connected to the instance to disconnect. If any database instances are connected to the Oracle ASM instance, then the SHUTDOWN command returns an error and leaves the Oracle ASM instance running. Because the Oracle ASM instance does not contain any transactions, the TRANSACTIONAL mode behaves the same as IMMEDIATE mode.

Question: 23

Examine the following ALTER command;
SQL> ALTER DISKGROUP dgroup1 UNDROP DISKS;
What is the purpose of the command?

A. It cancels all pending disk drops within the disk group.
B. It adds previously dropped disks back into the disk group.
C. It restores disks that are being dropped as the result of a DROP DISKGROUP operation.
D. It mounts disks in the disk group for which the drop-disk operation has already been completed.
E. It restores all the dropped disks in the disk group for which the drop-disk operation has already been completed.

Answer: A

Explanation:
The key point is PENDING.

Question: 24

A database instance is using an Automatic Storage Management (ASM) instance, which has a disk group, DGROUP1, created as follows:
SQL> CREATE DISKGROUP dgroup1 NORMAL REDUNDANCY
FAILGROUP controller1 DISK '/devices/diska1', '/devices/diska2'
FAILGROUP controller2 DISK '/devices/diskb1', '/devices/diskb2';
What happens when the whole CONTROLLER1 Failure group is damaged?

A. The transactions that use the disk group will halt.
B. The mirroring of allocation units occurs within the CONTROLLER2 failure group.
C. The data in the CONTROLLER1 failure group is shifted to the CONTROLLER2 failure group and implicit rebalancing is triggered.
D. The ASM does not mirror any data and newly allocated primary allocation units (AU) are stored in the CONTROLLER2 failure group.

Answer: C

Question: 25

Your database instance is running. You are not able to access Oracle Enterprise Manager Database Control because the listener is not started.
Which tool or utility would you use to start the listener?

A. Oracle Net Manager
B. Listener Control utility
C. Database Configuration Assistant
D. Oracle Net Configuration Assistant

Answer: B

Question: 26

View the Exhibit and examine the disk groups created at the time of migrating the database storage to Automatic Storage Management (ASM).
Why does the FRA disk group initially have more free space even though both DATA and FRA disk groups are provided with the same size?

A. Because the FRA disk group will not support dynamic rebalancing
B. Because the FRA disk group is not configured to support mirroring
C. Because disks in the FRA disk group are not formatted at this stage
D. Because the FRA disk group will support only a single size of allocation unit

Answer: B

Question: 27

What are three benefits of using ASM? (Choose three.)

A. Ease of disk administration and maintenance
B. Load balancing across physical disks
C. Software RAID-1 data redundancy with double or triple mirrors
D. Automatic recovery of failed disks

Answer: A, B, C

Question: 28

What components are present in an ASM instance? (Choose three.)

A. SGA
B. Database processes
C. Database datafiles
D. Control files
E. Database parameter file or SPFILE

Answer: A, B, E

Question: 29

Which of the following is a benefit of ASM fast disk resync?

A. Failed disks are taken offline immediately but are not dropped.
B. Disk data is never lost.
C. By default, the failed disk is not dropped from the disk group ever, protecting you from loss of that disk.
D. The failed disk is automatically reformatted and then resynchronized to speed up the recovery process.
E. Hot spare disks are automatically configured and added to the disk group.

Answer: A

Explanation:
ASM Fast Mirror Resync

Question: 30

What is the result of increasing the value of the parameter ASM_POWER_LIMIT during a rebalance operation?

A. The ASM rebalance operation will likely consume fewer resources and complete in a shorter amount of time.
B. The ASM rebalance operation will consume fewer resources and complete in a longer amount of time.
C. The ASM rebalance operation will be parallelized and should complete in a shorter amount of time.
D. There is no ASM_POWER_LIMIT setting used in ASM.
E. None of the above

Answer: C

Question: 31

What is the default AU size of an ASM disk group? What is the maximum AU size in an ASM disk group?

A. 100KB default, 10TB maximum
B. 256KB default, 1024MB maximum
C. 10MB default, 126PB maximum
D. 64KB default, 1EB maximum
E. 1MB default, 64MB maximum

Answer: E

Explanation:
The AU size is determined at creation time with the allocation unit size (AU_SIZE) disk group attribute. The values can be 1, 2, 4, 8, 16, 32, and 64 MB.
Refer to here

Question: 32

Which initialization parameter in an ASM instance specifies the disk groups to be automatically mounted at instance startup?

A. ASM_DISKMOUNT
B. ASM_DISKGROUP
C. ASM_DISKSTRING
D. ASM_MOUNTGROUP

Answer: B

Explanation:
Refer to here
When you run the STARTUP command, this command attempts to mount the disk groups specified by the initialization parameter ASM_DISKGROUPS. If you have not entered a value for ASM_DISKGROUPS, then the ASM instance starts and Oracle displays an error that no disk groups were mounted. You can then mount disk groups with the ALTER DISKGROUP...MOUNT command.

Question: 33

When an ASM instance receives a SHUTDOWN NORMAL command, what command does it pass on to all database instances that rely on the ASM instances disk groups?

A. TRANSACTIONAL
B. IMMEDIATE
C. ABORT
D. NORMAL

Answer: C

Question: 34

When starting up your ASM instance, you receive the following error:
SQL> startup pfile=$ORACLE_HOME/dbs/init+ASM.ora
ASM instance started
Total System Global Area 104611840 bytes
Fixed Size 1298220 bytes
Variable Size 78147796 bytes
ASM Cache 25165824 bytes
ORA-15032: not all alternations performed
ORA-15063: ASM discovered an insufficient number of disks for diskgroup “DGROUP3”
ORA-15063: ASM discovered an insufficient number of disks for diskgroup “DGROUP2”
ORA-15063: ASM discovered an insufficient number of disks for diskgroup “DGROUP1”
In trying to determine the cause of the problem, you issue this query:
SQL> show parameter asm

What is the cause of the error?

A. The ASM_DISKGROUPS parameter is configured for three disk groups: DGROUP1, DGROUP2, and DGROUP3.
The underlying disks for these disk groups have apparently been lost.
B. The format of the ASM_DISKGROUPS parameter is incorrect. It should reference the disk group numbers, not the names of the disk groups
C. The ASM_POWER_LIMIT parameter is incorrectly set to 1. It should be set to the number of disk groups being attached to the ASM instance.
D. The ASM_DISKSTRING parameter is not set; therefore disk discovery is not possible.
E. There is insufficient information to solve this problem.

Answer: D

Explanation:
ASM_DISKSTRING specifies an operating system-dependent value used by Automatic Storage Management to limit the set of disks considered for discovery. When a new disk is added to a disk group, each Automatic Storage Management instance that has the disk group mounted must be able to discover the new disk using the value of ASM_DISKSTRING.
In most cases, the default value will be sufficient. Using a more restrictive value may reduce the time required for Automatic Storage Management to perform discovery, and thus improve disk group mount time or the time for adding a disk to a disk group. A "?" at the beginning of the string gets expanded to the Oracle home directory. Depending on the operating system, wildcard characters can be used. It may be necessary to dynamically change ASM_DISKSTRING before adding a disk so that the new disk will be discovered.
An attempt to dynamically modify ASM_DISKSTRING will be rejected and the old value retained if the new value cannot be used to discover a disk that is in a disk group that is already mounted.
Refer to here

Question: 35

As DBA for the Rebalance, you have decided that you need to facilitate some redundancy in your database. Using ASM, you want to create a disk group that will provide for the greatest amount of redundancy for your ASM data (you do not have advanced SAN mirroring technology available to you, unfortunately).
Which of the following commands would create a disk group that would offer the maximum in data redundancy?

Answer: C

Explanation:
No SAN mirroring available means no external redundancy available.
The highest redundancy of ASM is the HIGH redundancy with 3 mirror copies.