OCA Assessment Test

OCA Assessment Test

OCA Assessment Test

 

    这两天开始复习OCP了，先从OCA开始，打算花1个月时间，读完《OCA:Oracle 10g™ Administration I Study Guide》这本书。今天看了个开头，做了份评估测试。总共40道题，在不翻书不做实验的情况下，发现居然错的题比对的还要多……原来自己对知识的掌握非常有欠缺啊。把没做对的题都收录下来，等看完书之后再来做一遍，希望到时候能够觉得很easy。

 

 

1. Which of the following components is not part of an Oracle instance?

A. System Global Area
B. Server Process
C. Database Writer
D. System Monitor

 

B. The Server Process that is started on the server on behalf of each user connection is not considered
part of the instance. An instance is defined as the System Global Area and all the Oracle
background processes.

 

 

 

5. You are a database administrator with databases in New York, Hong Kong, and London. You
want to administer all your databases from a central console using Grid Control. Which of the
following commands do you issue when using Grid Control?

 

A. emctl start grid
B. emctl start dbconsole
C. emctl start agent
D. isqlplusctl start

 

C. When you are using the Grid Control, start the agent on each managed target machine. The
emctl start agent command initiates the agent process.

 

 

 

8. You are in the middle of an emergency drill at your organization. There is little time to notify
database users, and you need to stop the Oracle database processes as quickly as possible. Which
of the following would you perform?

 

A. SHUTDOWN ABORT
B. SHUTDOWN TRANSACTIONAL
C. SHUTDOWN
D. SHUTDOWN IMMEDIATE
E. None of the above

A. Given the circumstances, the quickest way to shut down the Oracle processes is a SHUTDOWN
ABORT. This is not the preferred shutdown method and requires instance recovery upon startup.
For more information,

 

 

 

10. Which of the following objects share the same namespace and therefore cannot have the same name?

 

A. Tables and sequences
B. Tables and indexes
C. Tables and tablespaces
D. Tables and constraints

 

A. Tables share a namespace with views, sequences, private synonyms, procedures, functions,
packages, materialized views, and user-defined types. Objects sharing a namespace cannot have
the same name.

 

 

 

12. Oracle Advanced Security provides all the following except:

 

A. Database profiles
B. Data encryption
C. Checksumming
D. Biometrics option

 

A. The Oracle Advanced Security feature provides additional database security options such as
encryption, checksumming, and user authentication via options such as the biometrics. This feature
is not necessary to use database profiles.

 

 

 

13. You have just issued the command lsnrctl stop LISTENER. Which of the following statements
are not true? (Choose all that apply.)

 

A. New connections to the default listener will not succeed.
B. Existing client connections will not be affected.
C. Only new dedicated connections will fail
D. Existing shared server connections will be dropped.

 

C, D. When you stop a listener, you affect only new client connections and not existing client
connections, so C and D are false. For more information

 

 

14. You issue the following command from the database server: sqlplus scott/tiger and
receive the following error message: ORA-01034: Oracle not available. What is the state
of the Oracle database:

 

A. The database is open but in restricted mode.
B. The instance is started but is in MOUNT mode.
C. The database and the instance are not started.
D. The instance is started in NOMOUNT mode.

 

C. Whenever you receive an ORA-01034, both the database and the instance are not started.

 

 

 

15. You connect to the database using the command sqlplus scott/[email protected]:1522/orcl .
To which database are you connecting?

 

A. abc.com
B. tiger
C. orcl
D. scott
E. None of the above

 

C. The database is the parameter supplied after the port designation. Therefore, you connect
to the orcl database.

 

 

 

16. You are administering an Oracle database using Shared Server. The LARGE_POOL_SIZE is
50MB. You issue the command ALTER SYSTEM SET LARGE_POOL_SIZE = 100M SCOPE=MEMORY.
You then shut down and restart the database. What will the LARGE_POOL_SIZE be?

 

A. 50MB
B. 100MB
C. The default LARGE_POOL_SIZE
D. The LARGE_POOL_SIZE as you have set it in the Oracle SPFILE that you are using

 

D. The LARGE_POOL_SIZE setting is determined by the setting in the Oracle SPFILE. Oracle
always reads this file on startup if you are using it. The SCOPE=MEMORY parameter means that only
the currently running instance is affected by the change. --卑鄙啊

 

 

 

17. You have decided to implement connection pooling and set a timeout limit of 20 minutes for idle
connections. You also want to support 500 concurrent connections with a maximum of 1500
sessions per dispatcher. Which of the following commands will accomplish this?

 

A. Dispatchers = "(PRO=TCP)(DIS=5)(POO=ON)(TICK=20)(CONN=500)(SESS=1500)"
B. Dispatchers = "(PRO=TCP)(DIS=5)(POO=ON)(TICK=2)(CONN=500)(SESS=1500)"
C. Dispatchers = "(PRO=TCP)(DIS=5)(POO=ON)(TICK=20)(CONN=1500)(SESS=500)"
D. Dispatchers = "(PRO=TCP)(DIS=5)(POOLING=ON)(TICK=20)(CONN=500)(SESS=1500)"

 

B. You would set the PRO, DIS, POO, TICK, CONN, and SESS attributes of the DISPATCHERS parameter
accordingly. Remember that the TICK measurement is in 10-minute increments.

 

 

18. You issue the command lsnrctl services. What pieces of information can you see regarding
shared server connections for each dispatcher listed? (Choose all that apply.)

 

A. Established connections
B. Refused connections
C. Idle connections
D. Current connections
E. All the above

 

A, B, D. You can see established, refused, and current connections for each dispatcher when
you issue this command. You can also see the maximum number of connections allowed per dispatcher
and the state of each dispatcher.

 

 

 

19. What status would you expect to see when querying V$DISPATCHER for a dispatcher that is not
currently servicing any client requests?

 

A. IDLE
B. WAIT
C. SLEEP
D. READY
E. None of the above

 

B. The WAIT status indicates that the dispatcher is waiting to process a client request.

 

 

 

23. Which of the following parameters directs Data Pump export to capture the table definitions for,
but not the contents of the tables owned by user sacagawea?

 

A. owner= sacagawea rows=no
B. schemas= sacagawea content=metadata_only
C. owner= sacagawea content=metadata_only
D. tablespaces= sacagawea data=no

 

B. The schemas parameter tells Data Pump export which object owners to include in the
extract. The content parameter tells Data Pump what to export: DATA_ONLY, METADATA_ONLY,
or ALL. The METADATA_ONLY value tells Data Pump to capture the object definitions but not the
stored data values.

 

 

26. When a table is updated, where is the before-image information (which can be used for undoing
the changes) stored?

 

A. Temporary segment
B. Redo log buffer
C. Undo buffer
D. Undo segment

 

D. Before any DML operation is marked as complete, the undo information (the before image of
data) is stored in the undo segments. This information is used to undo the changes and to provide
a read-consistent view of the data.

 

 

 

28. Select the invalid statements from the following regarding undo segment management. (Choose
all that apply.)

 

A. ALTER SYSTEM SET UNDO_TABLESPACE = ROLLBACK;
B. ALTER DATABASE SET UNDO_TABLESPACE = UNDOTBS;
C. ALTER SYSTEM SET UNDO_MANAGEMENT = AUTO;
D. ALTER SYSTEM SET UNDO_MANAGEMENT = MANUAL;

 

B, C, D. Choice A is the only valid statement; an undo tablespace can have any name that follows
the Oracle standard naming conventions for identifiers. Choice B is incorrect because undo
tablespaces are not managed using ALTER DATABASE. Choices C and D are incorrect because the
parameter UNDO_MANAGEMENT cannot be changed while the instance is running.

 

 

 

30. The Automatic Workload Repository (AWR) is primarily populated with performance statistics
by which Oracle 10g background process?

 

A. MMNL
B. QMN1
C. MMON
D. MMAN

 

C. The Memory Monitor (MMON) process gathers performance statistics from the SGA
(System Global Area) and stores them in the AWR. MMNL (Memory Monitor Light) also does
some AWR-related statistics gathering, but not to the extent that MMON does. QMN1 is the
process that monitors Oracle advanced queuing features. MMON is the process that dynamically
manages the sizes of each SGA component when directed to make changes by the ADDM
(Automatic Database Diagnostic Monitoring).

 

 

 

31. Which of the following advisors is used to determine if the database read-consistency mechanisms
are properly configured?

 

A. Undo Management Advisor
B. SQL Access Advisor
C. SQL Tuning Advisor
D. Memory Advisor

 

A. You can use the Undo Management Advisor to monitor and manage the undo segments to
ensure maximum levels of read consistency and minimize occurrences of ORA-01555: Snapshot
Too Old error messages.

 

 

32. You’ve decided to monitor your databases for CPU utilization based on baseline metrics. If you
specify that you want a warning alert sent whenever CPU utilization is greater than 50 percent
of the baseline and the high value for this metric is 300, when will the alert be sent?

 

A. Whenever CPU utilization is 250 or less
B. Whenever the CPU utilization is 450 or higher
C. Whenever the CPU utilization is 300 or higher
D. Whenever the CPU utilization is 225 or higher

 

B. The alert threshold will be defined as 300 * ( 1 + 50/100), or 450 percent.

 

 

 

33. Every evening you use SQL*Loader to perform direct-path loads of data into your company’s
data warehouse. Last night the load of the SALES table failed because the tablespace where the
SALES table is stored ran out of space. As a result, the indexes on the SALES table are in an unusable
state. Which of the following can you use to fix this problem?

 

A. Drop and re-create the affected indexes.
B. Use the ALTER INDEX … REBUILD command to rebuild the index.
C. Use EM Database Control to rebuild the index.
D. Any of the above will return the index to a usable state.

 

D. Dropping or rebuilding an index changes the index from an unstable to a usable state.

 

 

 

34. Which backup options are available for databases in NOARCHIVELOG mode? (Choose all that apply.)

 

A. Online, incremental
B. Offline, incremental
C. Online, full, whole database
D. Offline, full, whole database

 

D. If the database is in NOARCHIVELOG mode, only offline, full, whole database backups can be
performed. As a result, any database failure loses committed transactions since the last backup.

 

 

 

36. Identify the types of backups in the following list that RMAN performs. (Choose all that apply.)

 

A. Backups to flat files
B. Image copies
C. Data Pump export dumps
D. Backup sets

 

B, D. RMAN can make image copies of datafiles or place backups into backup sets.

 

 

 

37. Archived log files can be written to as many as _______ locations. (Choose the best answer.)

 

A. Ten, but they all have to be local, or they all have to be remote.
B. Ten, with a maximum of five local destinations and five remote destinations
C. Ten total
D. Five total
E. Twenty, a maximum of ten local destinations, and ten remote destinations

 

C. Archived redo log files can be written to as many as ten different destinations, with any combination
of local and remote locations.

 

 

 

39. If the database instance fails, but will not shut down, you must use which command(s) before
instance recovery can be performed? (Choose the best answer.)

 

A. STARTUP NOMOUNT
B. STARTUP MOUNT
C. SHUTDOWN IMMEDIATE; STARTUP FORCE
D. SHUTDOWN ABORT; STARTUP

 

D. Instance recovery is performed automatically when ever the database instance is terminated
without a NORMAL or IMMEDIATE shutdown. To force an abnormal termination of
the instance, you must use SHUTDOWN ABORT and then you can use STARTUP to initiate automatic
instance recovery. STARTUP NOMOUNT and STARTUP MOUNT will not start up an instance
unless it is shut down first. STARTUP FORCE does not need a SHUTDOWN IMMEDIATE command
first; it first performs a SHUTDOWN ABORT and then attempts a normal STARTUP.

 

 

 

40. Which of the following is not a valid database state?

 

A. OPEN
B. SHUTDOWN
C. STARTUP
D. MOUNT
E. NOMOUNT

 

C. STARTUP is not a valid state, but the command used to start the database. --仔细读题啊