OCP读书笔记(21)

youngfan007

　　Administer ASM disk groups
Back up the recovery catalog
Configure backup settings
Configure, Monitor Flashback Database and Perform Flashback Database operations
Create a job, program, and schedule
Create a multisection,compressed and encrypted backup
Create an archival backup for long-term retention
Create and use a virtual private catalog
Create lightweight jobs
Creating a duplicate database
Create and use Database Resource Manager Components
Create duplex backup and back up backup sets
Create lightweight jobs
Creating a duplicate database
Describe Automatic Storage Management (ASM)
Describe the concepts of transportable tablespaces and databases
Enable fast incremental backup
Identify the need of backup mode
Perform Flashback Query
Perform complete recovery from a critical or noncritical data file loss using RMAN
Perform Block Media Recovery
Reclaim wasted space from tables and indexes by using the segment shrink functionality
Recover using a backup control file
Recover from a lost redo log group
Recover using incrementally updated backups
Restore a database onto a new host
Set up and use a Flashback Data Archive
Set up initialization parameter files for ASM and database instances
Start up and shut down ASM instances
Tuning RMAN
Understand Database Replay
Use job chains to perform a series of related tasks
Use the SQL Access Advisor to tune a workload
Use Flash Recovery Area
Use Flashback Transaction
Use a time-based or event-based schedule for executing Scheduler jobs

　　3.Your database is in ARCHIVELOG mode. You have two online redo log groups, each of which contains one redo member. When you attempt to start the database, you receive the following errors:
　　ORA-00313: open failed for members of log group 1 of thread 1
　　ORA-00312: online log 1 thread 1: 'D:\REDO01.LOG'
　　You discover that the online redo log file of the current redo group is corrupted.
　　Which statement should you use to resolve this issue?
　　A. ALTER DATABASE DROP LOGFILE GROUP 1;
　　B. ALTER DATABASE CLEAR LOGFILE GROUP 1;
　　C. ALTER DATABASE CLEAR UNARCHIVED LOGFILE GROUP 1;
　　D. ALTER DATABASE DROP LOGFILE MEMBER 'D:\REDO01.LOG';
　　Answer: C
　　11.View the Exhibit to examine the metrics with a threshold. Which statement is true regarding the
　　Number of Transactions (per second) metric?
　　
　　A. Oracle uses statistical relevance to determine when an adaptive threshold has been breached for the metric.
　　B. The statistics for the metric values observed over the baseline time period are not examined to
　　determine threshold values.
　　C. Oracle determines when an adaptive threshold has been breached based on the maximum value
　　captured by the baseline.
　　D. The total concurrent number of threshold violations, which must occur before an alert is raised for the metric, has been set to zero.
　　Answer: A
　　Adaptive thresholds enable you to monitor and detect performance issues while minimizing administrative overhead. Adaptive thresholds can automatically set warning and critical alert thresholds for some system metrics using statistics derived from metric values captured in the moving window baseline. The statistics for these thresholds are recomputed weekly and might result in new thresholds as system performance evolves over time. In addition to recalculating thresholds weekly, adaptive thresholds might compute different thresholds values for different times of the day or week based on periodic workload patterns.
　　14.Which two statements are true regarding hot patching? (Choose two.)
　　A. It requires relinking of the Oracle binary.
　　B. It does not require database instance shutdown.
　　C. It can detect conflicts between two online patches.
　　D. It is available for installing all patches on all platforms.
　　E. It works only in a single database instance environment.
　　Answer: B,C

　　15.You are in the process of creating a virtual private catalog in your Oracle Database 11g database. The
　　PROD1, PROD2, and PROD3 Oracle Database 10g databases are registered in the base recovery
　　catalog. The database user who owns the base recovery catalog is CATOWNER. CATOWNER executes
　　the following command to grant privileges to a new user VPC1 using Oracle Database 11g RMAN
　　executables:
　　RMAN> GRANT CATALOG FOR DATABASE prod1, prod2 TO vpc1;
　　Then you issue the following commands:
　　RMAN> CONNECT CATALOG vpc1/oracle@catdb;
　　RMAN> SQL "EXEC catowner.dbms_rcvcat.create_virtual_catalog;"
　　What is the outcome of the above commands?
　　A. They execute and create a virtual catalog for pre-Oracle 11g clients.
　　B. They produce an error because PROD1 and PROD2 databases belong to the older version.
　　C. They produce an error because you need to connect as CATOWNER to execute this packaged
　　procedure.
　　D. They produce an error because you need to connect to the target database to execute this packaged procedure.
　　Answer: A

　　19.A PL/SQL procedure queries only those columns of a redefined table that were unchanged by the
　　online table redefinition. What happens to the PL/SQL procedure after the online table redefinition?
　　A. It remains valid.
　　B. It becomes invalid for all options of online table redefinition but automatically gets revalidated the next
　　time it is used.
　　C. It becomes invalid for all options of online table redefinition and is automatically recompiled during
　　online redefinition of the table.
　　D. It becomes invalid only if the storage parameters have been modified and it automatically gets
　　revalidated the next time it is used.
　　Answer: A

　　22.An index called ORD_CUSTNAME_IX has been created on the CUSTNAME column in the ORDERS
　　table using the following command:
　　SQL>CREATE INDEX ord_custname_ix ON orders(custname);
　　The ORDERS table is frequently queried using the CUSTNAME column in the WHERE clause. You want
　　to check the impact on the performance of the queries if the index is not available. You do not want the
　　index to be dropped or rebuilt to perform this test.
　　Which is the most efficient method of performing this task?
　　A. disabling the index
　　B. making the index invisible
　　C. making the index unusable
　　D. using the MONITORING USAGE clause for the index
　　Answer: B

　　24.Which of the following information will be gathered by the SQL Test Case Builder for the problems pertaining to SQL-related problems? (Choose all that apply.)
　　A. ADR diagnostic files
　　B. all the optimizer statistics
　　C. initialization parameter settings
　　D. PL/SQL functions, procedures, and packages
　　E. the table and index definitions and actual data
　　Answer: B,C,E

　　答案解析：
　　参考：http://docs.oracle.com/cd/E11882_01/server.112/e41573/sql_overview.htm#PFGRF16001
　　此题答案有误，E错误，不包含actual data。
　　正确答案应该为BCD
Building SQL Test Cases
　　For many SQL-related problems, obtaining a reproducible test case makes it easier to resolve the problem. Starting with the 11g Release 2 (11.2), Oracle Database contains the SQL Test Case Builder, which automates the somewhat difficult and time-consuming process of gathering and reproducing as much information as possible about a problem and the environment in which it occurred.
　　SQL Test Case Builder captures information pertaining to a SQL-related problem, along with the exact environment under which the problem occurred, so that you can reproduce and test the problem on a separate database. After the test case is ready, you can upload the problem to Oracle Support to enable support personnel to reproduce and troubleshoot the problem.
　　The information gathered by SQL Test Case Builder includes the query being executed, table and index definitions (but not the actual data), PL/SQL functions, procedures, and packages, optimizer statistics, and initialization parameter settings.
　　
　　27.You are using the flash recovery area (fast recovery area in 11g Release 2) to store backup related
　　files in your database.
　　After regular monitoring of space usage in the flash recovery area. You realize that the flash recovery
　　area is jetting filled up very fast and it is running out of space. Your database flash recovery area is low
　　on specie and you have no more room on disk. Proactively, which two options could you use to make
　　more space available in the flash recovery area [Choose two]
　　A. Change the RMAN archived log deletion policy.
　　B. Use the RMAN CROSSCHECK command to reclaim the archived log space.
　　C. Change the RMAN retention policy to retain backups for a shorter period of time.
　　D. Use OS command to move files from the flash recovery area to some other location
　　Answer:B,D
　　32.In your production database, you:
　　-Are using Recovery Manager (RMAN) with a recovery catalog to perform the backup operation at regular intervals Set the control file autobackup to "on"
　　-Are maintaining image copies of the database files
　　You have lost the server parameter tile (SPFILE) and the control file. Which option must you consider before restoring the SPFILI: and the control file by using the control file autobackup?
　　A. setting DBID for the database
　　B. using the RMAN SWITCH command
　　C. using the RMAN SET NEWNAME command
　　D. starting up the database Instance In the NOMOUNT state
　　Answer:C
　　34.Examine the following RMAN command:
　　BACKUP DATABASE
　　TAG TESTDB
　　KEEP UNTIL 'SYSDATE+1'
　　RESTORE POINT TESTDB06;
　　Which two statements are true regarding the backup taken by using the above RMAN command?
　　(Choose two.)
　　A. Only data files and the control file are backed up.
　　B. Archived redo logs are backed up only if the database is open during the backup.
　　C. The backup is deleted after one day, regardless of the default retention policy settings.
　　D. The backup becomes obsolete after one day, regardless of the default retention policy settings.
　　Answer: B, D

　　36.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: AD
　　答案解析：
　　参考：http://docs.oracle.com/cd/E11882_01/server.112/e18951/asm_util004.htm#OSTMG01644
　　39.View the Exhibit to examine the Automatic SQL Tuning result details. Which action would you suggest for the selected SQL statement in the Exhibit?
　　
　　A. Accept the recommended SQL profile.
　　B. Collect statistics for the related objects.
　　C. Run the Access Advisor for the SQL statement.
　　D. Run the Segment Advisor for recommendations.
　　SQL 优化指导会分别考察指导任务中包括的每个SQL 语句。创建一个新索引可能会对查询有帮助，但也可能增加DML 的响应时间。因此，应使用SQL 访问指导检查建议的索引或其它对象对工作量（一组SQL 语句）的影响，以确定性能是否有净提高。
　　Answer: C

　　40.Evaluate the following code:
　　SQL>VARIABLE task_name VARCHAR2(255); SQL>VARIABLE sql_stmt VARCHAR2(4000);
　　SQL>BEGIN :sql_stmt := 'SELECT COUNT(*) FROM customers
　　WHERE cust_state_province =''CA''';
　　:task_name := 'MY_QUICKTUNE_TASK';
　　DBMS_ADVISOR.QUICK_TUNE(DBMS_ADVISOR.SQLACCESS_ADVISOR,
　　:task_name, :sql_stmt);
　　END;
　　What is the outcome of this block of code?
　　A. It creates a task and workload, and executes the task.
　　B. It creates a task and workload but does not execute the task.
　　C. It produces an error because a template has not been created.
　　D. It produces an error because the SQL Tuning Set has not been created.
　　Answer: A

　　DBMS_ADVISOR.QUICK_TUNE (
　　   advisor_name           IN VARCHAR2,
　　   task_name              IN VARCHAR2,
　　   attr1                  IN CLOB,
　　   attr2                  IN VARCHAR2 := NULL,
　　   attr3                  IN NUMBER := NULL,
　　   task_or_template       IN VARCHAR2 := NULL);
　　Usage Notes
　　If indicated by the user, the final recommendations can be implemented by the procedure.
　　The task will be created using either a specified SQL Access task template or the built-in default template of SQLACCESS_GENERAL. The workload will only contain the specified statement, and all task parameters will be defaulted.
　　attr1 must be the single SQL statement to tune. For the SQL Access Advisor, attr2 is the user who would execute the single statement. If omitted, the current user will be used.

　　42.You plan to use SQL Performance Analyzer to analyze the SQL workload. You created a SQL Tuning
　　Set as a part of the workload capturing. What information is captured as part of this process? (Choose all
　　that apply.)
　　A. the SQL text
　　B. the execution plan
　　C. the execution context
　　D. the execution frequency
　　E. the system change number (SCN)
　　Answer: ACD
　　参考：http://www.oracle.com/technetwork/cn/articles/o69ocp-099954.html
　　While creating the SQL tuning set, SQL Performance Analyzer captures the SQL text, the execution context, and the number of times the statement is executed. SQL Performance Analyzer then uses that information to analyzethe performance of the SQL statement.
　　45.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
　　In previous releases, Oracle ASM used the disk with the primary copy of a mirrored extent as the preferred disk for data read operations. With this release, using the new initialization file parameter asm_preferred_read_failure_groups, you can specify disks located near a specific cluster node as the preferred disks from which that node obtains mirrored data. This option is presented in DBCA, or you can configure it after installation. This change facilitates faster processing of data with widely distributed shared storage systems or with extended clusters (clusters whose nodes are geographically dispersed), and improves disaster recovery preparedness.
　　46.What happens when you run the SQL Tuning Advisor with limited scope?
　　A. Access path analysis is not performed for SQL statements.
　　B. SQL structure analysis is not performed for SQL statements.
　　C. SQL Profile recommendations are not generated for SQL statements.
　　D. Staleness and absence of statistics are not checked for the objects in the SQL Tuning Advisor.
　　Answer: C
　　47.You issue the following command on the RMAN prompt.
　　REPORT NEED BACKUP DAYS 5;
　　Which statement is true about executing this command?
　　A. It will display a list of files that need incremental backup
　　B. It will display a list of files that need backup after five days
　　C. It will display a list of files that were backed up in the last five days
　　D. It will display a list of files that have not been backed up in the last five days
　　E. It will apply the current retention policy to determine the files that need to be backed up
　　Answer: D
　　50.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

　　When some disks in a disk group are offline, the disk group can't be mount without the force option.
　　54.Evaluate the following function code:
　　CREATE FUNCTION get_dept_avg(dept_id NUMBER) RETURN NUMBER RESULT_CACHE
　　RELIES_ON (EMPLOYEES) IS
　　avgsal NUMBER(6);
　　BEGIN
　　SELECT AVG(SALARY)INTO avgsal
　　FROM EMPLOYEES
　　WHERE DEPARTMENT_ID = dept_id;
　　RETURN avgsal;
　　END get_dept_avg;
　　Which statement is true regarding the above function?
　　A. The cached result becomes invalid when any structural change is done to the EMPLOYEES table.
　　B. If the function execution results in an unhandled exception, the exception result is also stored in the cache.
　　C. Each time the function is invoked in a different session, the current result in the result cache gets
　　overwritten.
　　D. If the function is invoked with a different parameter value, the existing result in the result cache gets overwritten by the latest value.
　　Answer: A

　　If the result for get_dept_avg (10) is in the result cache, the result is returned from the cache; otherwise, the result is computed and added to the cache. Because get_dept_info depends on the  EMPLOYEES table, any committed change to EMPLOYEES invalidates all cached results for get_dept_avg
　　55.Following is the list of locations in random order where oranfstab can be placed.
　　1./etc/mtab
　　2.$ORACLE_HOME/dbs/oranfstab
　　3./etc/oranfstab
　　What is the sequence in which Direct NFS will search the locations?
　　A. 1, 2, 3
　　B. 3, 2, 1
　　C. 2, 3, 1
　　D. 1, 3, 2
　　Answer: C
　　Direct NFS Client determines mount point settings to NFS storage devices based on the configurations in /etc/mnttab, which are changed with configuring the/etc/fstab file.
　　Direct NFS Client searches for mount entries in the following order:

• $ORACLE_HOME/dbs/oranfstab
  
• /etc/oranfstab
  
• /etc/mnttab
  

　　Direct NFS Client uses the first matching entry found.
　　Oracle Database is not shipped with Direct NFS Client enabled by default. To enable Direct NFS Client, complete the following steps:

• Change the directory to $ORACLE_HOME/rdbms/lib.
  
• Enter the following command:
  

　　make -f ins_rdbms.mk dnfs_on
　　Note:
　　You can have only one active Direct NFS Client implementation for each instance. Using Direct NFS Client on an instance will prevent another Direct NFS Client implementation.
　　58.Which statement is true when Automatic Workload Repository (AWR) baselines are created using
　　baseline templates?
　　A. AWR baselines are always created as repeating baselines.
　　B. AWR baselines can be created on the basis of two time values.
　　C. AWR baselines are always created with infinite expiration duration.
　　D. AWR baselines are always created using the Automatic Workload Repository (AWR) retention period
　　as expiration duration.
　　Answer: B
　　62.You want to convert your existing non-ASM files to ASM files for the database PROD. Which method or command would you use to accomplish this task?
　　A. Data Pump Export and Import
　　B. conventional export and import
　　C. the CONVERT command of RMAN
　　D. the BACKUP AS COPY. command of RMAN
　　Answer: D
　　参考使用rman将表空间转移到ASM存储区：http://blog.iyunv.com/rlhua/article/details/14107309
　　66.Which two initialization parameters would you set to enable Automatic Shared Memory Management?
　　(Choose two.)
　　A. set SHARED_POOL_SIZE to zero
　　B. set STATISTICS_LEVEL to BASIC
　　C. set SGA_TARGET to a non-zero value
　　D. set DB_CACHE_SIZE to a non-zero value
　　E. set STATISTICS_LEVEL to TYPICAL or ALL
　　Answer: C, E

　　You enable the automatic shared memory management feature by setting the SGA_TARGET parameter to a nonzero value. This parameter sets the total size of the SGA. It replaces the parameters that control the memory allocated for a specific set of individual components, which are now automatically and dynamically resized (tuned) as needed.
　　Note:
　　The STATISTICS_LEVEL initialization parameter must be set to TYPICAL (the default) or ALL for automatic shared memory management to function.
　　77.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
　　下面的列表讲述了与ASM 相关的 SHUTDOWN命令参数。
　　· NORMAL：ASM 在卸载所有磁盘组并关闭ASM 实例之前，将等待任何正在进行的SQL 完成执行。在关闭实例之前，ASM 将等待所有当前连接的用户从该实例断开。如果任何数据库实例与ASM 实例连接，则 SHUTDOWN命令将返回错误并保持ASM 实例继续运行。NORMAL是默认关闭模式。
　　· IMMEDIATE或 TRANSACTIONAL：ASM 在卸载所有磁盘组并关闭ASM 实例之前，将等待任何正在进行的SQL 完成执行。ASM 不等待当前与实例连接的用户断开连接。如果任何数据库实例与ASM 实例连接，则 SHUTDOWN命令将返回错误并保持ASM 实例继续运行。
　　· ABORT：ASM 实例立即关闭，而不按顺序卸载磁盘组。这将导致下次启动ASM 时进行恢复操作。如果有任何数据库实例与ASM 实例连接，则该数据库实例也将中止。
　　注：有连接的RDBMS 实例时，不应用NORMAL、IMMEDIATE和 TRANSACTIONAL形式的关闭，而将返回下面的错误：
　　SQL> shutdown
　　ORA-15097: cannot SHUTDOWN ASM instance with connected client (process 14372)
　　ASM是依赖于CSS守护进程的，因此在启动ASM实例前要确保css守护进程已经启动  。  CSS(Cluster Synchronization Services) 守护进程用来维持ASM 及客户端数据库实例间的一致性同步，如果是通过dbca建库的话，那么CSS守护进程默认即会启动(跟随系统reboot)。
　　80.Which two statements regarding a SQL profile are true? (Choose two.)
　　A. It is built by Automatic Tuning Optimizer.
　　B. It cannot be stored persistently in the data dictionary.
　　C. It can be used by the query optimizer automatically.
　　D. It can be created manually by using the CREATE PROFILE command.
　　Answer: A, C
　　SQL profile
　　A collection of information that enables the query optimizer to create an optimal execution plan for a SQL statement.
　　SQL Profile Creation
　　When you accept a profile, the database creates the profile and stores it persistently in the data dictionary. If a user issues a statement for which a profile has been built, then the query optimizer (in normal mode) uses both the environment and the SQL profile to build a well-tuned plan.
　　If the database uses SQL plan management, and if a SQL plan baseline exists for the SQL statement, then the database adds a new plan to the baseline when a SQL profile is created. Otherwise, the database does not add a new plan baseline.

　　85.You executed the following command to drop a user:
　　DROP USER scott CASCADE;
　　Which two statements regarding the above command are correct? (Choose two.)
　　A. All the objects of scott are moved to the Recycle Bin.
　　B. Any objects in the Recycle Bin belonging to scott are purged.
　　C. All the objects owned by scott are permanently dropped from the database.
　　D. All the objects of scott in the Recycle Bin must be purged before executing the DROP command.
　　E. Any objects in the Recycle Bin belonging to scott will not be affected by the above DROP command.
　　Answer: B, C
　　DROP USER
　　Use the DROP USER statement to remove a database user and optionally remove the user's objects.
　　In an Oracle Automatic Storage Management (Oracle ASM) cluster, a user authenticated AS SYSASM can use this clause to remove a user from the password file that is local to the Oracle ASM instance of the current node.
　　When you drop a user, Oracle Database also purges all of that user's schema objects from the recycle bin.
　　Prerequisites
　　You must have the DROP USER system privilege. In an Oracle ASM cluster, you must be authenticated AS SYSASM.
　　user
　　Specify the user to be dropped. Oracle Database does not drop users whose schemas contain objects unless you specify CASCADE or unless you first explicitly drop the user's objects.
　　Restriction on Dropping Users
　　You cannot drop a user whose schema contains a table that uses a flashback data archive for historical tracking. You must first disable the table's use of the flashback data archive.
　　CASCADE
　　Specify CASCADE to drop all objects in the user's schema before dropping the user. You must specify this clause to drop a user whose schema contains any objects.
　　If the user's schema contains tables, then Oracle Database drops the tables and automatically drops any referential integrity constraints on tables in other schemas that refer to primary and unique keys on these tables.
　　If this clause results in tables being dropped, then the database also drops all domain indexes created on columns of those tables and invokes appropriate drop routines.
　　93.The database is configured in ARCHIVELOG mode and regular complete database backups are taken.
　　The loss of which two types of files may require a recovery with the RESETLOGS option? (Choose two)
　　A. Control files
　　B. Password files
　　C. Inactive online redo log file
　　D. Archived log files required to perform recovery
　　E. Newly created tablespace which is not backed up
　　Answer: A, D
　　95.Examine the following scenario: The target database instance is running. The most recent backup available for the target database was taken two days ago. Log files switches have occurred in last two days. The target database is duplicated on the same host, using the Recovery Manager (RMAN)duplicate command as follows:
　　RMAN> RUN { ALLOCATE AUXILIARY CHANNEL aux 1 DEVICE TYPE DISK;
　　DUPLICATE TARGET DATABASE TO auxdb; }
　　Which statement is true about the duplicate database in this scenario?
　　A. It contains data till the last backup
　　B. It contains all data from target database until the current time
　　C. It contains all data from only the committed transactions in the target database
　　D. It contains all data except that which is used by the transactions in the current online redo file of target database
　　Answer: D