OCP 1Z0-023 学习讨论区

upzero

which data dictionary view would you query to display the value of the NLS-SORT value initialized at start up?   D
A)        DBA-CATALOG
B)        NLS-SESSION-PARAMETER
C)        NLS-DATABASE-PARAMETERS
D)        NLS-INSTANCE-PARAMETERS
备注： d）display the values of NLS initialization parameters listed in the parameter file.

.according to the Optimal Architecture, how should you organize your DB files:  A
A)        directly below the oracle directory
B)        directly below the application directory
C)        directly below the oracle Server Directory
D)        within the appropriate product version directory
备注：The Optimal Flexible Architecture is a set of guidelines created by Oracle that provide a template for configuring oracle system.The OFA recommends that DB files be placed in directories directly below the oracle directory. DB file include datafiles, control files and redo log files.

whici Export utility keyword allows associated triggers to be included with a table during an Export when run by a privileges user? C
        A)ROWS  B)DIRECT  C)TABLES  D)PARFILE  E)CONSISTENT  F)CONSTRAINT

which benefit does oracle Fast Commit offer?  C
A)        transactions are immediately written to the datafiles
B)        smaller transactions are processed more quickly than large one
C)        minimal information is required to record the changes in the redo logs.
D)        Transactions requesting a COMMIT are given priority over other redo log records.
备注：oracle’s Fast Commit allows LGWR to record only the changes and SCN in the redo log files. The size of the transaction does not affect the time required to write to the redo log files. These writes are sequential and faster than writing entire blocks to the datafiles. Writes to the datafiles occur independently of the COMMIT.

upzero

What are three ways that data integrity can be maintained to ensure that data adhere to the business rules?  B  F
A)        DB tunning
B)        Application code
C)        DB triggers
D)        Index utilization
E)        DB backup and recovery
F)        Declare integrity constraints

which view would a query to display the value assigned to the MAXDATAFIELS parameter for the PROD database:  D
A)        V$database
B)        V$datafile
C)        V$controlfile
D)        V$controlfile-Record-Setction  (displays information stored in the control file)

which SHUTDOWN mode will only wait for the pending transaction of a correct user to end before ending their session:  D
        A)ABORT   B)NORMAL  C)IMMEDIATE  D)TRANSACTIONAL
备注: users will be unable to create new session ,no new transactions are allowed and users are not disconnected until their current transaction commits or roll back. When all the transactions have ended. The db is closed and dismounted and the instance is shut down.
Normal Mode: users will wait for all pending transactions to be end and all users to disconnect before shutting down the DB.

The steps to move a tablespace to a write-once device in the appropriate order:
1)        issue the ALTER TABLESPACE READ ONLY command
2)        use o/s commands to copy the file to the device
3)        issue the ALTER TABLESPACE RENAME DATAFILE command
备注：to move a tablespace to read-only media ,such a cd-rom or write-once (wrom) drivers:
(1)        issue the Alter tablespace read only command
(2)        use o/s commands to move the tablespace data files to the read-only device
(3)        issue the Alter Tablespace tablespace Rename Datafile command

upzero

1.Which script provides wrapped package code?
A)cat*.sql
B)utl*.sql
C)prvt*.sql  *
D)dbms*.sql
备注：
prvt*.plb is an administrative script and provides wrapped package code. Wrapped database package code is used to extend the oracle sever functionality.

dbms*.sql defines the database package specifications.
cat*.sql provides catalog and data dictionary information.
utl*.sql creates views and tables for database utilities.

2.which privileges is needed to assign a profile to an existing user?
A)Alter User *
B)Create User
C)Alter Profile
D)Create Profile
note:
To assign a profile to an existing user,issue the Alter User command.
To assing a profile to a new user,include the Profile clause in the Create User command.

3.What does the initialize parameter LOG_ARCHIVE_START indicate?
A)the number of redo log groups
B)if automatic archiving is enabled *
C)the destination of the archive log files
D)if the database is in NOARCHIVELOG mode
note:
The initialization parameter LOG_ARCHIVE_START indicates whether automatic archiving is enabled when an instance starts.A value of TRUE indicates that archiving is automatic.The ARCHIVE LOG LIST command to determine if automatic archiving enabled.

upzero

^_^,我觉得023这门很基础，是后面backup and recovery 以及performance and tuning的前提课程，因此这门不仅仅是过的问题哦，学习的时候要有为后面做准备的思想。我通过分数不是很高，因为我只是在考前做了一份sts 和bonson，但是我觉得还是有点经验可以交流的：
1。认真的复习student guide，最好能熟读2-3遍。
2。自己感觉不是很在行的关键章节，重点的再看看，最好的方法是配合实践动手看看。很多虚表你不知道其字段是什么，但你只要动手操作看看，就很有印象了。
3、考试前最好做一做练习，在练习中你能得到的最大收获是能及时的发现自己的那个知识点忘记或者模糊了，这样在返回到课本看看你就很容易理解了。

我能给的这门就这么多，希望大家还是以实践动手来掌握些实在的为好！
恒之，信之哦！

susan_j

最初由 upzero 发布
[B]^_^,我觉得023这门很基础，是后面backup and recovery 以及performance and tuning的前提课程，因此这门不仅仅是过的问题哦，学习的时候要有为后面做准备的思想。我通过分数不是很高，因为我只是在考前做了一份sts 和bonson，但是我觉得还是有点经验可以交流的：
1。认真的复习student guide，最好能熟读2-3遍。
2。自己感觉不是很在行的关键章节，重点的再看看，最好的方法是配合实践动手看看。很多虚表你不知道其字段是什么，但你只要动手操作看看，就很有印象了。
3、考试前最好做一做练习，在练习中你能得到的最大收获是能及时的发现自己的那个知识点忘记或者模糊了，这样在返回到课本看看你就很容易理解了。

我能给的这门就这么多，希望大家还是以实践动手来掌握些实在的为好！
恒之，信之哦！ [/B]

Thanks a lot

tonyxucanada

最初由 on323 发布
[B] [/B]

1: D
2: C

olive

dba_tables里面记录的是创建表时候的参数，实际的extent大小已被调整为32768，即minimum extent，查一下dba_extents就知道了。

最初由 takaka 发布
[B]实验环境：
OS：WIN2000 server
DB：ORACLE8 i  8.1.6
CONNECT SYSTEM/MANAGER

Oracle8i Enterprise Edition Release 8.1.6.0.0 - Production
With the Partitioning option
JServer Release 8.1.6.0.0 - Production
SQL> CREATE TABLESPACE TS_test2
  2  DATAFILE 'c:\DATA01.DBF' SIZE 2m
  3  MINIMUM EXTENT 30K
  4  LOGGING ONLINE PERMANENT

表空间已创建。

SQL> CREATE TABLE T_DATA
  2  (C1 NUMBER)
  3  TABLESPACE TS_TEST2
  4  STORAGE(INITIAL 20K
  5  NEXT 20K );

表已创建。

SQL> SELECT INITIAL_EXTENT FROM DBA_TABLES
  2  WHERE TABLE_NAME='T_DATA';

INITIAL_EXTENT
--------------
         24576

我实验的结果为
TS MINIMUM EXTENT=32K
TABLE INITIAL=24K

用OEM创建的话，干脆MINIMUM EXTENT为 0，
用OEM修改TS的存储中的MINIMUM EXTENT，显示SQL为
ALTER TABLESPACE "TS_TEST1" MINIMUM EXTENT 30K

我也不清楚如何解释这个问题，只是觉得可能和系统的某些default参数有关
请高手指教！ [/B]

olive

Oracle不断检查当前如果做recovery需要的i/o数目，如果超过了fast_start_io_target的数目，就触发一次ckpt。

最初由 leslie chen 发布
[B]fast_start_io_target = n 可以理解成每当读取了n个data block就应触发一次CKPT
log_checkpoint_internal = n 可以理解成每当读取了n个redo log block就应触发一次CKPT
log_checkpoint_timeout = n 可以理解成每隔多少秒就应触发一次CKPT (default is 1800)
ORACLE SERVER每次自动比较这三个值，取其中最近的一点产生CKPT [/B]

olive

这个例子来自sybex，但是我认为是错的。8i中该参数的意思是当前checkpoint不可以落后redo log file指定数量的block。
如果照这个例子，那我如果指定该参数为1，那岂不是要redo log file写了1999个block才触发checkpoint？岂不是变成这个参数越小checkpoint的触发越少了？而且这样一来还变得和redo log file的大小有关，如果redol og file是20000个block，同样设参数为1，难道要19999个block写满才触发？

最初由 freezr 发布
[B]

对于log_checkpoint_internal和log_checkpoint_timeout，你上面讲的都是ORACLE8中的意思，在8I中有所改变。log_check_internal的意思不再是每当LGWR写一定数量的BLOCK到REDO LOG BLOCK就触发CKPT，而是CKPT在REDO LOG FILE还差一定数量就要满时触发。举个例子，REDO LOG FILE的大小是2000个OS BLOCKS，如果此参数设定为500，那么REDO LOG FILE在1500个OS BLOCKS被写满时，产生CKPT。
同样，log_checkpoint_timeout也变成了这个意思。不再只是定时的间隔。变成checkpoint position in the redo log
file to a location where the end of the log file was this many seconds ago.
fast_start_io_target 是限制在DIRTY BUFFER的数量。为了限制恢复时所需的BLOCK数量。 [/B]

pjiang

最初由 Hollie 发布
[
   又一问题请教
   If the group is active,why you must wait a log switch or force a log switch before dropping one of ites members?
   谢谢！ [/B]

一旦系统发生 crash等事件时，做crash recovery and block recovery就要用到active group，so the active group cann't be dropped.
LGWR正在写的group 状态是current, 而不是active. Certainly ,the current group is aslo active implicitly .