Oracle OCP 1Z0-050（61-70题）解析
QUESTION 61:
Exhibit:
View the Exhibit to examine the parameters set for your database instance.
You execute the following command to perform I/O calibration after the declaration of bind variables in the session that are used in the command:
SQL> EXECUTE dbms_resource_manager.calibrate_io( num_physical_disks=>1, -
max_latency=>50, -
max_iops=>:max_iops, -
max_mbps=>:max_mbps, -
actual_latency=>:actual_latency);
Which statement describes the consequence?
A. The calibration process runs successfully and populates all the bind variables.
B. The calibration process runs successfully but the latency time is not computed.
C. The calibration process runs successfully but only the latency time is computed.
D. The command produces an error.
Answer: D
解析：
参考Oracle官方文档
https://docs.oracle.com/cd/B28359_01/appdev.111/b28419/d_resmgr.htm#CJGHGFEA
IO校准(IO Calibration)特性可以帮助我们了解存储系统的真实性能，以进一步判断I/O性能问题是由数据库还是存储系统自身引起的。I/O校准特性(IO Calibration)通过对Oracle数据文件的随机I/O访问存储介质，其结论值更符合数据库IO性能的真实情况。
QUESTION 62:
You upgraded Oracle Database 10g to Oracle Database 11g. How would this affect the existing users' passwords?
A. All passwords automatically become case-sensitive.
B. All passwords remain non-case-sensitive till they are changed.
C. All passwords remain non-case-sensitive until their password attribute in the profile is altered.
D. All passwords remain non-case-sensitive and cannot be changed.
Answer: B
https://docs.oracle.com/cd/E11882_01/network.112/e36292/authentication.htm#DBSEG30321
QUESTION 63:
While tuning a SQL statement, the SQL Tuning Advisor finds an existing SQL profile for the statement that has stale statistics available. What would the optimizer do in this situation?
A. It updates the existing SQL profiles with current statistics.
B. It logs a warning message in the alert log so that the DBA can perform statistics collection manually.
C. It initiates the statistics collection process by running GATHER_STATS_JOB.
D. It makes the statistics information available to GATHER_STATS_JOB.
Answer: D
QUESTION 64:
You executed the following PL/SQL block successfully:
VARIABLE tname VARCHAR2(20)
BEGIN
dbms_addm.insert_finding_directive (NULL, DIR_NAME=>'Detail CPU Usage',
FINDING_NAME=>'CPU Usage',
MIN_ACTIVE_SESSIONS=>0, MIN_PERC_IMPACT=>90);
:tname := 'database ADDM task4';
dbms_addm.analyze_db(:tname, 150, 162);
END;
/
Then you executed the following command:
SQL> SELECT dbms_addm.get_report(:tname) FROM DUAL;
The above command produces Automatic Database Diagnostic Monitor (ADDM) analysis ____.
A. with the CPU Usage finding if it is less than 90
B. without the CPU Usage finding if it is less than 90
C. with the CPU Usage finding for snapshots not between 150 and 162
D. with the CPU Usage finding for snapshots below 90
Answer: B
QUESTION 65:
You have a range-partitioned table in your database. Each partition in the table contains the sales data for a quarter. The partition related to the current quarter is modified frequently and other partitions undergo fewer data manipulations. The preferences for the table are set to their default values. You collect statistics for the table using the following command in regular intervals:
SQL> EXECUTE
DBMS_STATS.GATHER_TABLE_STATS('SH','SALES',GRANULARITY=>'GLOBAL');
You need statistics to be collected more quickly. What can you do to achieve this?
A. Set the STATISTICS_LEVEL parameter to BASIC.
B. Set the INCREMENTAL value to TRUE for the partition table.
C. Set DYNAMIC_SAMPLING to level 4.
D. Increase the value of STALE_PERCENT for the partition table.
Answer: B
解析：
参考Oracle官方文档
https://docs.oracle.com/cd/E11882_01/server.112/e25523/part_admin001.htm#VLDBG1086
QUESTION 66:
You create a new Automatic Database Diagnostic Monitor (ADDM) task: instance_analysis_mode_task. To view the ADDM report, you use the following command:
SQL> SELECT dbms_addm.get_report('my_instance_analysis_mode_task') FROM dual;
You want to suppress ADDM output relating to Segment Advisor actions on user SCOTT's segments. What would you do to achieve this?
A. Add a segment directive for the ADDM task.
B. Disable the Segment Advisor from the Automatic Maintenance Task.
C. Add a finding directive for the ADDM task.
D. Add a parameter directive for the ADDM task.
Answer: A
解析：
Automatic Database Diagnostic Monitor (ADDM)
Automatic Database Diagnostic Monitor (ADDM) is a self-diagnostic advisor built into Oracle Database. Using statistics captured in AWR, ADDM automatically and proactively diagnoses database performance and determines how identified problems can be resolved. You can also run ADDM manually.
ADDM takes a holistic approach to system performance, using time as a common currency between components. ADDM identifies areas of Oracle Database consuming the most time. For example, the database may be spending an excessive amount of time waiting for free database buffers. ADDM drills down to identify the root cause of problems, rather than just the symptoms, and reports the effect of the problem on Oracle Database overall. Minimal overhead occurs during the diagnostic process.
In many cases, ADDM recommends solutions and quantifies expected performance benefits. For example, ADDM may recommend changes to hardware, database configuration, database schema, or applications. If a recommendation is made, then ADDM reports the time benefit. The use of time as a measure enables comparisons of problems or recommendations.
Besides reporting potential performance issues, ADDM documents areas of the database that are not problems. Subcomponents such as I/O and memory that are not significantly impacting database performance are pruned from the classification tree at an early stage. ADDM lists these subcomponents so that you can quickly see that there is little benefit to performing actions in those areas.
参考Oracle官方文档：
https://docs.oracle.com/cd/E11882_01/server.112/e41573/diag.htm#PFGRF94250
QUESTION 67:
Evaluate the following SQL statement used to create the PRODUCTS table:
CREATE TABLE products
(product_id NUMBER(3) PRIMARY KEY,
product_desc VARCHAR2(25),
qty NUMBER(8,2),
rate NUMBER(10,2),
total_value AS ( qty * rate))
PARTITION BY RANGE (total_value)
(PARTITION p1 VALUES LESS THAN (100000),
PARTITION p2 VALUES LESS THAN (150000),
PARTITION p3 VALUES LESS THAN (MAXVALUE))
COMPRESS FOR ALL OPERATIONS;
Which statement is true regarding this command?
A. It produces an error because compression cannot be used for the TOTAL_VALUE partition key.
B. It executes successfully but partition pruning cannot happen for this partition key.
C. It produces an error because the TOTAL_VALUE column cannot be used as a partition key.
D. It executes successfully but the values in the TOTAL_VALUE column would not be physically stored in the partitions.
Answer: D
参考Oracle官方文档解释：
https://docs.oracle.com/en/database/oracle/oracle-database/index.html
https://docs.oracle.com/cd/E11882_01/appdev.112/e11822/adobjcol.htm#ADOBJ00608
QUESTION 68:
Exhibit:
View the Exhibit to examine the details for an incident.
Which statement is true regarding the status of the incident?
A. The incident has been newly created and is in the process of collecting diagnostic information.
B. The incident is now in the Done state and the ADR can select the incident to be purged.
C. The DBA is working on the incident and prefers that the incident be kept in the ADR.
D. The data collection for the incident is complete and the incident can be packaged and sent to Oracle Support.
Answer: D
QUESTION 69:
Which statement describes the significance of the CHANGE FAILURE command in RMAN? (Choose all that apply.)
A. It is used to change failure priority only for HIGH or LOW priorities.
B. It is used to execute the advised repair script.
C. It is used to change failure priority only for the CRITICAL priority.
D. It is used to explicitly close the open failures.
E. It is used to inform the database about the repair after the repair script executes.
Answer: A,D
参考Oracle官方文档解释：
https://docs.oracle.com/cd/E11882_01/backup.112/e10642/rcmrepai.htm#BRADV246
Failure Status
Every failure has a failure status: OPEN or CLOSED. The status of a failure is OPEN until the appropriate repair action is invoked. The status changes to CLOSED after the failure is repaired.
Every time you execute LIST FAILURE, Data Recovery Advisor revalidates all open failures and closes failures that no longer exist. Thus, if you fixed some failures as part of a separate procedure, or if the failures were transient problems that disappeared by themselves, running LIST FAILURE automatically closes them.
You can use CHANGE FAILURE to change the status of an open failure to CLOSED if you have fixed it manually. However, it makes sense to use CHANGE FAILURE ... CLOSED only if for some reason the failure was not closed automatically. If a failure still exists when you use CHANGE to close it manually, then Data Recover Advisor re-creates it with a different failure ID when the appropriate data integrity check is executed.
QUESTION 70:
Which statements describe the capabilities of the DBMS_NETWORK_ACL_ADMIN package? (Choose all that apply.)
A. It can be used to control the time interval for which the access privilege is available to a user.
B. It can be used to allow the access privilege settings for users but not roles.
C. It can be used to selectively restrict a user's access to different applications in a specific host computer.
D. It can be used to selectively restrict the access for each user in a database to different host computers.
E. It can be used to allow the access privilege settings for users as well as roles.
Answer: A,D,E
解析：
参考Oracle官方文档解释：
https://docs.oracle.com/cd/E11882_01/appdev.112/e40758/d_networkacl_adm.htm#ARPLS148
The DBMS_NETWORK_ACL_ADMIN package provides the interface to administer the network Access Control List (ACL).