102.Examine the following values of the initialization parameters in the database having the SID ORCL: BACKGROUND_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/bdump USER_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/udump CORE_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/cdump DIAGNOSTIC_DEST= The environment variables have the following value: ORACLE_BASE=/u01/app/oracle ORACLE_HOME=/u01/app/oracle/product/11.1.0/db_1 What is the location of the Automatic Diagnostic Repository (ADR) home? ADR目录 B. /u01/app/oracle 103.Observe the following PL/
sql block: BEGIN dbms_spm.configure('SPACE_BUDGET_PERCENT',30); END; Which statement is correct regarding the above PL/
sql block? D. It generates a weekly warning in the alert log file when SMB occupies more than 30% of the SYSAUX tablespace. DBMS_SPM包允许
用户使用
sql计划管理
功能来管理
sql执行计划,
sql计划管理
功能可以通过长时间的记录和分析
sql语句执行计划来有效的防止由于突然间更改一个
sql语句执行计划所导致
数据库性能的衰退,而且还可以通过已知的一组高效的执行计划
生成一些执行计划基线。这些
sql计划基线能够随后用于保证适当的
性能,即使是在系统发生改变的时候,通常在如下的情况使用
sql计划
功能来管理
sql执行计划: 1.
数据库升级安装改变优化器时,通常会有少部分的执行计划改变,大部分可能是有变化的或者是有提高的。无论怎样,还是存在一部分的计划改变所导致
性能的衰退问题。此时利用
sql计划基线能显著地减少由于
数据库更新带来的
性能问题。 2. 正在运行的系统和不断变化的数据会带来一些
性能问题。利用
sql计划基线能可以减少
性能回退同时可以维持系统稳定 3. 有时部署新的系统模块相当于引用新的
sql语句到系统中,应用程序需要有适当的
sql执行计划,而这些新的执行计划需要通过一些标准的测试获得,使用
sql计划基线能在随时间的变化产生更好的
性能 语句日志、计划历史记录和
sql 计划基准都存储在
sql 管理库中。
sql 管理库是数 据库字典的组成部分,存储在 SYSAUX 表空间中。默认情况下,
sql 管理库的空间限 制为不超过 SYSAUX 表空间的 10% 。但是, 可以使用 PL/
sql 过程 DBMS_SPM.CONFIGURE 将这一限制
修改为 1% 至 50% 之间的任意值。
后台进程每周 测量一次
sql 管理库的占用空间,超过定义的限制时,将在警报日志中
生成警告。 每周还要执行定期清理任务,来管理
sql 管理库内部的 SPM 使用的磁盘空间。在维护 时段
自动运行该任务,任何超过 53 周一直未使用过的计划都将被清理,从而确保那些即 使每年仅运行一次的所有语句保持可用。可以使用 DBMS_SPM.CONFIGURE 或企业管理 器
修改未使用计划的保留时间;保留时间值的范围可以是 5 至 523 周(稍长于 10 年)。
sql>exec dbms_spm.configure(‘SPACE_BUDGET_PERCENT’,20);
sql>exec dbms_spm.configure(‘PLAN_RETENTION_WEEKS’,100); col PARAMETER_NAME for a20 col LAST_MODIFIED for a20 col MODIFIED_BY for a20 / PARAMETER_NAME PARAMETER_VALUE LAST_MODIFIED MODIFIED_BY -------------------- --------------- -------------------- -------------------- SPACE_BUDGET_PERCENT 10 PLAN_RETENTION_WEEKS 53 2 rows selected. select * from DBA_
sql_MANAGEMENT_CONFIG; PARAMETER_NAME PARAMETER_VALUE LAST_MODIFIED MODIFIED_BY -------------------- --------------- -------------------- -------------------- SPACE_BUDGET_PERCENT 10 PLAN_RETENTION_WEEKS 53 104.You are managing an Oracle Database 11g ASM instance having three disks in a disk group with ASM compatibility attribute set to 11.1.0 and redundancy set to high. One of the disks in the disk group becomes unavailable because of power failure. Which statements will be true in this scenario? (Choose all that apply.) B. The ASM tracks the extents that are modified during the outa 跟踪在outa期间被更改的区 D. The disk automatically goes offline.
自动离线 Answer: BD 正在管理一个Oracle11g
数据库的ASM实例,该实例的ASM兼容
属性设置为11.1.0且冗余设置为高的磁盘组中有三个磁盘。因为停电其中一个磁盘组中的磁盘变得不可用。在这种情况下哪些描述是真实的? B,
自动储存管理跟踪在OUTA期间被
修改的区。 D,磁盘会
自动脱机 Disks 磁盘组创建时使用CREATE DISKGROUP 语句, 创建时允许我们设置冗余项: Ÿ NORMAL REDUNDANCY - Two-way mirroring,requiring two failure groups. Ÿ HIGH REDUNDANCY - Three-way mirroring,requiring three failure groups. Ÿ EXTERNAL REDUNDANCY - No mirroring for disks that are already protected using hardware mirroring or RAID. If you have hardware RAID it should be used in preference to ASM redundancy,so this will be the standard option for most installations. Fast Mirror Resync 在短暂的磁盘故障发生时,ASM 保持跟踪记录那些要被写入掉线的磁盘中所改变的部分; 一旦磁盘再次可以使用时,那些改变的部分变被再次的同步到磁盘中, 而不是被覆写全盘的
内容;这种机制可以适当的加快重新同步数据的效率;
快速镜像同步(fast mirror resync) 这种机制仅仅在磁盘组的 compatibility attributes 被设置为 11.1 or higher才生效 How ASM Manages Disk Failures 取决于磁盘组的冗余级别和定义的故障组,一个或多个的故障磁盘可能导致以下结果之一: 1.首先磁盘被下线随后被
自动的下线;在这种情况下磁盘组一直挂载着并且提供着服务;另外由于镜像的存在,所有的磁盘组的信息保持健康的状态;随后在磁盘移除的操作之后,ASM执行一个再平衡调整用于重建全部的冗余项来恢复那些在坏掉的磁盘的上的数据 2.全部的磁盘组
自动的卸载,这意味着丢失掉的数据的可访问性 所以选择B,D 105.Which statements are true regarding table compression? (Choose all that apply.) 表压缩 A. It saves disk space and reduces memory usage. C. It incurs extra
cpu overhead during DML as well as direct loading operations. Answer: AC Table Compression
数据库可以使用表压缩来剔除在一个数据块中重复的值;对于数据冗余量很高的表,压缩即可以节省磁盘空间,还可以节省内存中对database buffer cache 的使用,同时在某些情况下提高
查询效率;表压缩是一种易懂的
数据库操作 Basic and OLTP Table Compression 基于数据字典的表压缩提供了更高的压缩比率,oracle
数据库支持如下的压缩类型: 基本的表压缩 这种类型压缩那些通过直接路径加载的数据,
支持有限的数据类型和
sql操作 OLTP表压缩 这种类型的压缩专为OLTP应用和压缩任何被
sql操作的数据所设计的
数据库存储压缩行使用row-major格式。所有列的一行存储在一起,其次是所有列的下一行,等等。重复的值用一个简短符号表替换并存储在块的开始部分。因此,在数据块本身信息需要重新创建未压缩的数据存储。 压缩数据块看起来很像正常的数据块。大多数在常规数据块的
数据库特性、
功能、工作,同样适用于压缩块。 所以选 A,C A选项,根据上述的解释可以了解到表的压缩会节省内存中对database buffer cache 的使用 所以A正确,B
错误 C选项,有压缩就一定会有额为的
cpu计算消耗,这是必然的结果,且无论是在DML操作时还是直接加载时 D解压操作不是在I/O中进行的,而是在
cpu计算结果 106.You are working as a DBA on the decision support system. There is a business requirement to track and store all transactions for at least three years for a few tables in the database. Automatic undo management is enabled in the database. Which configuration should you use to accomplish this task? 有一些表 需要记录 跟踪 存储过去三年里面的所有的事务
自动undo管理已开 需要怎么配置 A. Enable Flashback Data Archive for the tables. 表闪回归档开启 107.Which components are needed for successful and most efficient recovery. A. The backup RB3 and the current online redo log files 备份和当前在线重做日志 108.You are managing an Oracle Database 11g instance with ASM storage. You lost an ASM disk group DATA. You have RMAN backup of data as well as ASM
Metadata backup. You want to re-create the missing disk group by using the ASMCMD md_restore command. Which of these methods would you use to achieve this? (Choose all that apply.) B. Restore the disk group with the exact configuration as the backed-up disk group,using the same disk group name,same set of disks,and failure group configurations. C. Restore the disk group with changed disk group specification,failure group specification,disk group name,and other disk attributes. D. Restore
Metadata in an existing disk group by passing the existing disk group name as an input parameter. Answer: BCD md_restore恢复磁盘组元数据备份 ASM元数据备份与恢复:md_backup和md_restore 109.Which statement describes the effect of table redefinition重新定义 on the triggers attached to the table? A. All triggers on the table are invalidated无效 and are automatically revalidated重新生效 with the next DML execution on the table. 110.You plan to collect the Automatic Workload Repository (AWR) data every Monday morning for a month. You want Oracle Database to automatically create a baseline every Monday and remove the old baseline. What is the correct action to achieve this? 每周一收集AWR数据, 每周一创建基线,并
删除 C. Create a repeating baseline template 创建重复基线模板 111.Which three statements are true regarding persistent lightweight jobs? (Choose three.) B. The user cannot set privileges on persistent lightweight jobs. C. Persistent lightweight jobs are useful when users need to create a large number of jobs in a short time. E. The use of a template is mandatory to create persistent lightweight jobs. 轻量级作业: 也成为持久性轻量级作业,如果当我们的
数据库每秒钟需要创建、
删除或
修改数十个或数百个作业时,使用轻量级作业是降低开销的最佳
方法, 常规作业: 是由oracle 11g Scheduler 所
支持的作业,常规作业需要很多的系统开销,因为他们必须由Scheduler创建且每次执行完由Scheduler
删除,常规作业提供了使用诸如其它
用户程序的优点,并且提供了对运行此作业的权限细粒度控制 轻量级作业有别于常规作业的特征如下: 1.轻量级作业不是
数据库对象,不会产生创建或
删除轻量级作业时多引起的开销 2.与普通作业相比,创建和
删除轻量级作业的时间少的很多; 3.轻量级作业的作业元数据和运行时数据占用的磁盘空间很少; 4.由于占用的磁盘空间少,可以再RAC环境中平衡轻量级作业的
负载; 轻量级作业有几个缺点: 1.无法设置轻量级作业的权限,作业的权限从模板的计划继承而来 2.由于轻量级作业使用模板,无法创建完全独立的轻量级作业,我们必须使用PL/
sql命令创建轻量级作业,而无法用过EM创建 创建轻量级作业: 我们可以使用DBMS_SCHEDULER.CREATE_PROGRAM创建于轻量级作业一起使用的模板,供轻量级作业的模板存储为PL
sql_BLOCK或STORED_PROCEDURE类型的计划,创建轻量级作业时,指定LIGHEWERGHT的JOB_STYLE。JOB_STYLE的默认值是REGULAR 例: Normal 0 7.8 磅 0 2 false false false EN-US ZH-CN X-NONEbegin dbms_scheduler.create_job (job_name => 'lightweight_job1',template => 'test_prog',repeat_interval => 'freq=daily;by_hour=9',end_time =>'30-DC-09 12.00.00 AM Australia/Sydney',job_style => 'LIGHTWEIGHT',comments => 'New lightweight job'); end; / A选项,对于普通的作业而言,Oracle为作业创建包含相应元数据的
数据库对象,
修改几个
数据库表,然后
生成redo log。轻量级作业的作业元数据和运行时数据的要求极低 B选项,轻量级作业作业的权限从模板的计划继承而来 ,所以正确 C 选项,轻量级作业在用于短时间内创建或更改较多作业时使用的 D 相对于C,此选项
错误 E 创建轻量级作业时是必须使用模板的 112.Your database initialization parameter file has the following entry: SEC_MAX_
Failed_LOGIN_ATTEMPTS=3 Which statement is true regarding this setting? A. It drops the connection after the specified number of login attempts fail for any user. 尝试3次后 丢掉连接 113.Which statement is true regarding virtual private catalogs? D. To perform most of the RMAN operations,the virtual catalog owner must have the SYSDBA or SYSOPER privilege on the target database. 完成大多数RMAN操作,虚拟目录在目标库上必须有SYSDBA权限或者SYSOPER权限 Answer: D 114.Which tasks can be accomplished using the Enterprise Manager Support Workbench in Oracle Database 11g? (Choose all that apply.) B. You can track the Service Request (SR) and implement repairs. C. You can package and upload diagnostic data to Oracle Support. D. You can manually run health checks to gather diagnostic data for a problem. 115.What are the advantages of variable extent size support for large ASM files? (Choose two.)
支持大ASM
文件的可变区大小的优势是什么? C. Fewer extent pointers are needed to describe the file and less memory is
required to manage the extent maps in the shared pool. D. This feature enables faster file opens because of the reduction in the amount of memory that is
required to store file extents. Answer: CD C.只需要较少的区指针就可以描述
文件以及只需要较少的内存去管理在共享池中的区映像。 D.此
功能可以更快地打开
文件,因为需要存储
文件区的内存量减少。 Extents The contents of Oracle ASM files are stored in a disk group as a set,or collection,of extents that are stored on individual disks within disk groups. Each extent resides on an individual disk. Extents consist of one or more allocation units (AU). To accommodate increasingly larger files,Oracle ASM uses variable size extents. Variable size extents enable support for larger Oracle ASM data files,reduce SGA memory requirements for very large databases,and improve performance for file create and open operations. The initial extent size equals the disk group allocation unit size and it increases by a factor of 4 or 16 at predefined thresholds. This feature is automatic for newly created and resized data files when specific disk group compatibility attributes are set to 11.1 or higher. The extent size of a file varies as follows: Extent size always equals the disk group AU size for the first 20000 extent sets (0 - 19999). Extent size equals 4*AU size for the next 20000 extent sets (20000 - 39999). Extent size equals 16*AU size for the next 20000 and higher extent sets (40000+). 116.Which two are the uses of the ASM
Metadata backup and restore (AMBR) feature? (Choose two.) C. It can be used to gather information about a preexisting ASM disk group with disk paths,disk name,failure groups,attributes,templates,and alias directory structure. D. It can be used to re-create the ASM disk group with its attributes. ASM 元数据备份和还原(AMBR) 有两种运行模式: 1)在备份模式下,AMBR 会分析ASM 固定表和视图来收集有关现有磁盘和故障组配置、模板以及别名目录结构的信息;然后,将此元数据信息转储至某个文本
文件。 2)在还原模式下,AMBR 会读取以前
生成的
文件来重建磁盘组及其元数据。可以在还原模式下控制AMBR 行为以完成full、nodg 或newdg 还原。这三种子模式间的差别在于是否需要
包括磁盘组创建并更改其特性 117.Which two changes and their effect on the system can be tested by using the Database Replay feature? (Choose two.) C. database and operating system upgrades
升级 D. changing the database storage to ASM-managed storage 改变存储 Answer: CD DatabaseReplay将生产系统上的负荷进行采集后还原到测试系统上进行重放,这个特性有助于我们在
数据库升级、主机参数
修改、
数据库参数
修改等重大变更实施前在测试系统上完全仿照生产系统的负荷进行全面的测试,量化评估出变更实施后对现有的
性能的影响程度。 Database Replay实施的流程是workload_capture->workload preprocess->replay client prepare->replay->generate replay report,对于同一个capture可以进行多次replay 实施过程中需要的服务器如下: 生产
数据库服务器:用于workload_capture,即
负载捕获 测试
数据库服务器:用于workload_ preprocess和replay,即
负载预处理和
负载重放 Replay client:用于发起workload的客户端进程 118.Which is the source used by Automatic
sql Tuning that runs as part of the AUTOTASK framework? B.
sql statements based on the AWR top
sql identification 哪个原因可以将Automatic
sqltuning作为autotask架构下的组成部分来使用 B.
sql statementsbased on the AWR top
sql identification 基于AWR top
sql鉴定中的
sql语句 119.While performing the backup of the flash recovery area,you notice that one of the archived redo log files is missing. You have multiple destinations for archived redo log files. What implications does it have on the backup of the flash recovery area? D. The backup succeeds because it fails over to one of the alternative archived redo log destinations. Answer: D 当执行FRA备份时,你注意到其中某个归档重做日志
文件已经丢失。你有多个归档重做日志
文件存储路径。它在FRA备份上的影响是: D. The backupsucceeds because it fails over to one of the alternative非正常的,二选一的 archived redo logdestinations.备份成功因为它有二选一的归档重做日志目标。 120.You are managing an Oracle Database 11g instance and an Oracle Database 10g instance on the same machine. Both instances use the ASM instance as storage. Which statement regarding the ASM disk group compatibility attributes are true in this scenario? (Choose all that apply.) A. The database-compatibility version settings for each instance must be greater than or equal to the RDBMS compatibility of all ASM disk groups used by that database instances. 每一个实例的
数据库兼容性版本设置必须大于或等于被
数据库实例所使用的所有的ASM磁盘组的RDBMS的兼容性 B. RDBMS compatibility and the database version determines whether a database instance can mount the ASM disk group. RDBMS兼容性和
数据库版本决定了一个
数据库实例是否可以mount一个ASM磁盘组。 D. ASM compatibility controls which features for the ASM will be enabled. ASM的兼容性控制
功能将启用 Answer: ABD (Choose all that apply.)你正在管理一个oracle11g实例和oracle10的实例(在相同的机器上)。两个实例都使用ASM实例作为存储。在个场景下关于ASM磁盘组兼容性
属性描述正确的是: 121.Which three statements are true regarding the functioning of the Autotask Background Process (ABP)? (Choose three.) Autotask BackgroundProcess(ABP)的
功能描述正确的是: B. It translates tasks into jobs for execution by the scheduler. 它把任务转换成通过调度器执行的job C. It determines the list of jobs that must be created for each maintenance window. 它决定了为每一个维护窗口所创建的job的列表 D. It is spawned by the MMON background process at the start of the maintenance window.在维护窗口开始之初由MMON
后台进程来引起 ABP相当于
自动任务与调度程序之间的中介,其主要作用是将
自动任务转换成Autotask作业,供调度程序执行。同样重要的是,ABP还维护所有任务执行的历史记录。ABP将其专用资料档案库存储在sysaux表空间中,您可以通过DBA_AUTOTASK_TASK 查案该资料档案库。 ABP是在启动维护窗口时,有MMON 启动的,所有实例只需要一个ABP。MMON进程将监视ABP,并在必要时重启ABP. ABP可以确定为每项维护任务创建的作业列表,此列表按以下优先级排序:紧急、高级、中级。在每个优先级组中,作业是按执行的首选顺序排列的。 ABP按照以下方式创建作业:先创建所有紧急优先级的作业,然后创建高优先级的作业,最后创建所有中优先级的作业。 ABP将作业分配到多个调度程序作业类。这些作业类将作业映射到基于优先级的使用者组。 注意:使用Oracle DB 11g时,不存在与特定任务永久关联的作业。因此,不能使用DBMS_SCHEDULER过程来控制
自动任务的行为,请改而使用DBMS_AUTO_TASK_ADMIN过程 122.Which statements are true regarding the concept of problems and incidents in the fault diagnosability可诊断性 infrastructure架构 for Oracle Database 11g? (Choose all that apply.) 在oracle11g的故障诊断架构中的问题和事件的
内容描述正确的是: C. The database sends an incident alert to the Oracle Enterprise Manager Database Home page.
数据库发送一个事件警告到oracle EM
数据库home
页面 D. Every problem has a problem key,which is a text string that describes the problem. 每个问题有一个问题key,描述问题的文本字符串 E. The database makes an entry into the alert log file when problems and incidents occur. Answer: CDE
数据库写个entry到alert日志
文件,当问题和事件发生的时候。 123.What two statements are true regarding the recommendations received from the
sql Access Advisor? (Choose two.) 来自
sql access advisor的推荐方案,描述正确的两句是 B. It can recommend partitioning on tables provided that the workloads have some predicates预测 and joins on the columns of the NUMBER or DATE type. 他可以推荐表分区(表的
负载有一些断定和连接在number或日期类型的列上) C. It can recommend partitioning only on tables that have at least 10,000 rows. 它可以推荐分区表至少有1W行上的表。 Answer: BC
sql accessadvisor推荐方案都有哪些??
sql Tuning Advisor 粒度最小的调整工具. 将一条或多条
sql语句做为输入
内容,分析所有访问路径,然后
生成改进
sql语句的建议,并提出索引,物化视图和分区方案来提高应用程序的总体
性能。 另外,在维护窗口中,Oracle也会针对Automatic Workload Repository(AWR) 来确定和记录的高
负载语句
自动化运行
sql Tuning Advisor
sql Access Advisor 它涉及工作量中所有
sql语句,并提出索引,特化视图和分区方案来提高应用程序的总体
性能。 124.You are managing Oracle Database 11g with an ASM storage with high redundancy. The following command was issued to drop the disks from the dga disk group after five hours: ALTER DISKGROUP dga OFFLINE DISKS IN FAILGROUP f2 DROP AFTER 5H; Which statement is true in this scenario? 高冗余ASM D. All the disks in the dga disk group in failure group f2 would be OFFLINE and the DISK_REPAIR_TIME disk attribute would be set to 5 hours. 将磁盘组dga中属于故障组f2的磁盘离线,并将DISK_REPAIR_TIME(磁盘修复时间)设置为5小时, 你正用具有高冗余的ASM存储来管理Oracle11g
数据库。 五个小时后发出下面的命令去从DGA磁盘组中
删除磁盘:
修改DGA磁盘组 ,离线磁盘, 在f2故障组, 5小时后
删除; D.在F2故障组的DGA磁盘组中的所有磁盘将下线且磁盘修复时间磁盘
属性将设置到5个小时 将磁盘组dga中属于故障组f2的磁盘离线,并将DISK_REPAIR_TIME(磁盘修复时间)设置为5小时 125.Which statement describes the significance意义 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. 答案A正确,CHANGE FAILURE 命令只能将故障优先级从HIGH 更改为LOW 和从LOW 更改为HIGH; 答案B不正确,CHANGE FAILURE 命令改变了级别后,就不能在修复范围之内了。 答案C不正确,CHANGE FAILURE 命令用于更改故障优先级或
关闭一个或多个故障,只能将故障优先级从HIGH 更改为LOW 和从LOW 更改为HIGH。当更改CRITICAL 优先级时会出现
错误。 答案D正确,可以显式
关闭打开的故障。 D. It is used to explicitly close the open failures. CHANGE FAILURE 命令用于更改故障优先级或
关闭一个或多个故障,只能将故障优先级从HIGH 更改为LOW 和从LOW 更改为HIGH。当更改CRITICAL 优先级时会出现
错误。(将故障的优先级从HIGH 更改为LOW 的一个原因是为了避免该故障
显示在LIST FAILURE 命令的默认
输出列表中。例如,如果块损坏具有HIGH 优先级,则该块位于很少使用的表空间中时,您可能希望将其临时更改为LOW。)修复故障后,将隐式
关闭打开的故障。但是,也可以显式
关闭故障。这需要重新评估其它所有打开的故障,因为其中的某些故障会因故障
关闭而变得不相关。默认情况下,该命令要求
用户确认请求的更改。 126.Which statements are true regarding the creation of an incident package file by using the EM Workbench Support? (Choose all that apply.) A. You can add or remove the trace files to the package. B. You can create the incremental incident package ZIP file for new or modified diagnostic information for the incident package already created. C. You can add
sql test cases to the incident package. Answer: ABC 127.The application tables owned by the user TEST in a test database need to be exported to the APPS schema in the production database by using Data Pump. Which option of Data Pump Import would you use to accomplish this? 数据泵导入导出 D. remap_schema Answer: D 128.You want to track and store all transactional changes to a table over its lifetime. To accomplish this task,you enabled Flashback Data Archive with the retention of 5 years. After some time,the business requirement changed and you were asked to change the retention from 5 years to 3 years. To accomplish this,you issued the following command: ALTER FLASHBACK ARCHIVE fla1 MODIFY RETENTION 3 YEAR; What is the implication of this command? 改变保留时间从5年到3年 D. All historical data older than three years is purged from the flashback archive FLA1. 超过三年的数据到彻底
删除 129.You are managing an Oracle Database 11g database with ASM storage. The ASM disk group has the COMPATIBLE.ASM attribute set to 11.1. Which statements are true regarding extent management and allocation units in the ASM disk group? (Choose all that apply.) A. The au_size disk group attribute determines the size of allocation units in the disk group. D. Extent management is completely automated. Allocation Units Every Oracle ASM disk is divided into allocation units (AU). An allocation unit is the fundamental unit of allocation within a disk group. A file extent consists of one or more allocation units. An Oracle ASM file consists of one or more file extents. When you create a disk group,you can set the Oracle ASM allocation unit size with the AU_SIZE disk group attribute. The values can be 1,2,4,8,16,32,or 64 MB,depending on the specific disk group compatibility level. Larger AU sizes typically provide performance advantages for data warehouse applications that use large sequential reads. http://docs.oracle.com/cd/E11882_01/server.112/e18951/asmcon.htm#BABDEIJI Extents The contents of Oracle ASM files are stored in a disk group as a set,Oracle ASM uses variable size extents. Variable size extents enable support for larger Oracle ASM data files,and improve performance for file create and open operations. The initial extent size equals the disk group allocation unit size and it increases by a factor of 4 or 16 at predefined thresholds. This feature is automatic for newly created and resized data files when specific disk group compatibility attributes are set to 11.1 or higher. 130.Which are the prerequisites先决条件 for performing flashback transactions on your database? (Choose all that apply.) B. Supplemental log must be enabled for the primary key. C. Supplemental log must be enabled. D. Execute permission on the DBMS_FLASHBACK package must be granted to the user. Answer: BCD 131 36 / 193 C. All historical data is purged and the new flashback data archives are maintained for three years. D. All historical data older than three years is purged from the flashback archive FLA1. Answer: D 129.You are managing an Oracle Database 11g database with ASM storage. The ASM disk group has the COMPATIBLE.ASM attribute set to 11.1. Which statements are true regarding extent management and allocation units in the ASM disk group? (Choose all that apply.) A. The au_size disk group attribute determines the size of allocation units in the disk group. B. The allocation unit size may vary but the extent size is fixed. C. The allocation unit size and extent size are fixed for all the disks in a disk group and cannot be changed. D. Extent management is completely automated. Answer: AD 130.Which are the prerequisites for performing flashback transactions on your database? (Choose all that apply.) A. Undo retention guarantee for the database must be configured. B. Supplemental log must be enabled for the primary key. C. Supplemental log must be enabled. D. Execute permission on the DBMS_FLASHBACK package must be granted to the user. Answer: BCD 131.Exhibit: View the Exhibit to examine the parameter values. You are planning to set the value for the MEMORY_TARGET parameter of your database instance. What value would you assign? C. 362 MB 90+272M 132.You are managing an Oracle Database 11g database. You want to take the backup of MULT_DATA,a big file tablespace of size 100 TB on tape drive,but you have tapedrives of only 10 GB each. Which method would accomplish the task quickly and efficiently? D. intrafile parallel backup Answer: D RMAN 的新增
功能 对超大型
文件应用Intrafile 并行备份和还原 在备份单一大型数据
文件时,现在可以使用多个并行服务器进程和“通道”来有效地分配工作量。这种使用多个部分的
方法改善了备份的
性能。 133.You performed the RMAN database backup with the KEEP option. Which two statements are true regarding this backup? (Choose two.) A. The backup contains data files,the server parameter file,and the control file even if the control file autobackup is disabled. B. The KEEP option overrides the configured retention policy. 134.You are managing an Oracle Database 11g database. You want to take a backup on tape drives of the USERS tablespace that has a single data file of 900 MB. You have tape drives of 300 MB each. To accomplish the backup,you issued the following RMAN command: RMAN>BACKUP SECTION SIZE 300M TABLESPACE users; What configuration should be effected to accomplish faster and optimized backups by using the above command? A. The SBT channel must be configured,with the default parallelism setting for the SBT device set to 1. B. The COMPATIBLE initialization parameter for the database instance must be set to at least 10.0. C. The SBT channel must be configured,with the parallelism setting for the SBT device set to 3. D. The SBT channel must be configured,with the MAXPIECESIZE set to 300 MB. Answer:c 您管理Oracle
数据库11g的
数据库,您 要对一个900 MB数据
文件的
用户表空间采取磁带备份。你有300 MB的磁带驱动器。 为了完成备份,你发 出以下RMAN命令: RMAN>BACKUP SECTION SIZE 300M TABLESPACE users; 通过使用上述命令, 应当进行什么样的配置来实现更快和优化的备份? C.SBT通道必须被配置, SBT设备的并行设置应设置为3。 135.The ADMIN_EMP table has columns EMPNO,ENAME,DEPTNO,and SAL. It has a materialized view EMP_MV with a materialized log and an ENAME_IDX index on the ENAME column. You need to perform an online table redefinition on the ADMIN_EMP table to move it from the TBS1 tablespace to the TBS2 tablespace in the same schema. What action is
required for the dependent objects when you perform online redefinition on the table? A. The materialized view should have a complete refresh performed after the online table redefinition is completed. 物化视图完全更新 136.You issued the following command to mount the DATA disk group in restricted mode: ALTER DISKGROUP data MOUNT RESTRICT; What is the implication of this command? D. The client RDBMS instance cannot access the files in the disk group. Answer: D MOUNT Specify MOUNT to mount the disk groups in the local Automatic Storage Management instance. Specify ALL MOUNT to mount all disk groups specified in theASM_DISKGROUPS initialization parameter. File operations can only be performed when a disk group is mounted. RESTRICTED | NORMAL Use these clauses to determine the manner in which the disk groups are mounted. In the RESTRICTED mode,the disk group is mounted in single-instance exclusive mode. No other ASM instance in the same cluster can mount that disk group. In this mode the disk group is not usable by any ASM client. In the NORMAL mode,the disk group is mounted in shared mode,so that other ASM instances and clients can access the disk group. This is the default. 137.Your company wants to upgrade the current production database to the RAC environment. To perform testing before migrating to the RAC environment,you performed the workload capture on the production database to record the peak workload. You set up the test RAC database and want to replay the recorded workload on the testmachine. Note the following steps that you may require to replay the database workload: 1) Preprocess the captured workload. 2) Restart the database in RESTRICTED mode. 3) Set up the Replay Clients. 4) Restore the test database to the point when the capture started. 5) Remap connections. Arrange the steps
required in the correct sequence to accomplish this task on the test machine. A. 1,5,3 (2 is not
required.) 迁移到rac环境评估
负载工作量 步骤为:预处理工作量--然后重放工作量,重放工作量先决条件之一为还原
数据库--定制选项中的连接映射--设置重放客户机,开始重放工作量。 138.You are working on the APPDB database as a DB A. The database has a default Flashback Data Archive DFLA1 created on it. You issued the following command to drop the Flashback Archive FLA1: DROP FLASHBACK ARCHIVE fla1; What is the effect of this command? D. The Flashback Data Archive and historical data are dropped. Answer: D 139.Which two prerequisites are needed for performing workload capture and replay? (Choose two.) C. The database on which the workload is replayed has to be a restore of the original database to a specific SCN. D. setting up the directory to capture the workload Answer: CD
数据库回放 P766 捕获注意事项 在工作量记录的计划阶段要执行以下任务: • 检查
数据库备份策略,确保在记录开始时
数据库可被还原为StartSCN 。 • 计划捕获期间:根据应用情况和峰值期间选择捕获期间。可以使用现有的可管理性
功能,如
自动工作量资料档案库(AWR) 和活动会话历史记录(ASH) ,根据工作量历史记录选择一个恰当的期间。应谨慎计划捕获的开始时间,因为建议的操作是在捕获开始前
关闭并重新启动
数据库。 • 指定工作量捕获数据的位置。必须设置用于存储工作量捕获数据的目录。应提供充足的磁盘空间,因为磁盘空间不足时记录会停止。但是,在停止之前捕获的所有
内容仍可用于重放。 • 定义捕获过滤器,过滤掉不捕获的
用户会话。可以指定记录过滤器以跳过不应捕获的会话。 •
数据库重放
功能没有引入任何新的权限或
用户角色。记录
用户和重放
用户必须具有SYSDBA 权限或SYSOPER权限。这是因为仅具备SYSOPER权限或SYSDBA 权限的
用户才可以启动或
关闭开始记录的
数据库。还应分配正确的操作系统(OS) 权限,以便
用户能够访问记录、重放目录以及操作这些目录下的
文件。 重放注意事项 预处理阶段是必需的针对指定
数据库版本的一次性操作。创建了必需的元数据以后,可以按需要多次重放工作量。 必须还原重放
数据库,以便与工作量捕获开始时的捕获
数据库匹配。成功的重放取决于应用程序事务处理,该事务处理要访问与捕获系统上的数据相同的应用程序数据。可以选择使用时间点恢复、闪回和导入/ 导出来还原应用程序数据。 140.Which two statements are true regarding Health Monitor checks in Oracle Database 11g? (Choose two.) A. Health Monitor checks can be used to scan the contents of the redo log and archive logs for accessibility and corruption. B. Health Monitor checks can be used to verify the integrity of database files and report failures if these files are inaccessible,corrupt or inconsistent. Health Monitor Checks能够发现
文件损坏,物理、逻辑块损坏,undo、redo损坏,数据字典损坏等等。 Health Monitor Checks产生结果报告,它包含了
解决问题的办法 141.Exhibit: View the Exhibit for some of the current parameter settings. A user logs in to the HR schema and issues the following commands:
sql> CREATE TABLE emp (empno NUMBER(3),ename VARCHAR2(20),sal NUMBER(8,2));
sql> INSERT INTO emp(empno,ename) VALUES(1,'JAMES'); At this moment,a second user also logs in to the HR schema and issues the following command:
sql> ALTER TABLE emp MODIFY sal NUMBER(10,2); What happens in the above scenario? C. The second user's session waits for a time period before producing the resource busy error DDL_LOCK_TIMEOUT specifies a time limit for how long DDL statements will wait in a DML lock queue. The default value of zero indicates a status of NOWAIT. The maximum value of 1,000,000 seconds will result in the DDL statement waiting forever to acquire a DML lock. If a lock is not acquired before the timeout period expires,then an error is returned. 142.In which situations will the ASM
Metadata backup help you recover the ASM disk in a disk group? (Choose all that apply.) A. when one or more file directory paths are accidentally deleted from an ASM disk group D. when one or more disks in an ASM disk group are lost Answer: AD 在哪些情况下ASM元数据备份会帮你在一个磁盘组恢复ASM磁盘? A.当一个或多个
文件目录路径从ASM磁盘组被意外
删除 D.当ASM磁盘组中的一个或多个磁盘丢失时 144.In your database,the RESULT_CACHE_MODE parameter has been set to MANUAL in the initialization parameter file. You issued the following command:
sql>SELECT /*+ RESULT_CACHE */ sale_category,sum(sale_amt) FROM sales GROUP BY sale_category; Where would the result of this query be stored? B. shared pool 在您的
数据库中,结果高速缓存模式参数已经在初始化 参数
文件中设为手动。你发出以下命令:
sql>SELECT /+ RESULT_CACHE / sale_category,sum(sale_amt) FROM sales GROUP BY sale_category; 此
查询的结果将被储存在哪里? B.共享池 The server result cache is a memory pool within the shared pool. This pool contains a
sql query result cache,which stores results of
sql queries,and a PL/
sql function result cache,which stores values returned by PL/
sql functions. RESULT_CACHE_MODE specifies when a ResultCache operator is spliced into a query's execution plan. Values: MANUAL The ResultCache operator is added only when the query is annotated (that is,hints). FORCE The ResultCache operator is added to the root of all SELECT statements (provided that it is valid to do so). Shared Pool Concepts The main components of the shared pool are the library cache,the dictionary cache,and,depending on your configuration,the server result cache. The library cache stores the executable (parsed or compiled) form of recently referenced
sql and PL/
sql code. The dictionary cache stores data referenced from the data dictionary. The server result cache stores the results of queries and PL/
sql function results. 145.You need to perform an online table redefinition of an existing SALES table to partition it into two tablespaces TBS1 and TBS2. The SALES table has a materialized view,materialized log,indexes,referential integrity constraint,and triggers with the PRECEDES clause existing on it. What action is
required for dependent objects when you perform online table redefinition? A. The dependent materialized view should have a complete refresh performed after the online table redefinition process. 表SALES 分区到两个表空间TBS1和TBS2 有物化视图, 对于数据仓库,创建的物化视图通常情况下是聚合 视图,单一表聚合视图和连接视图。 物化视图有很多方面和索引很相似:使用物化视图 的目的是为了提高
查询性能;物化视图对应用透明,增 加和
删除物化视图不会影响应用程序中
sql语句的正确 性和有效性;物化视图需要占用存储空间;当基表发生 变化时,物化视图也应当刷新 146.You want to take the backup of the USERS tablespace. It has a single data file of 900 MB. You have tape drives of 300 MB each. The SBT channel is configured for the RMAN. To accomplish the backup,you issued the following RMAN command: RMAN> BACKUP SECTION SIZE 300M TABLESPACE users; Which two statements are true regarding the execution of the above command? (Choose two.) B. The backup piece size will be limited to 300 MB. C. The operation is accomplished using the default channel available 147.You installed Oracle Database 11g afresh重新再度. Which statements are true regarding the default audit settings in this database? (Choose all that apply.) A. The audit trail is stored in an operating system file. B. Auditing is disabled for all privileges. C. The audit trail is stored in the database. 审计跟踪保存在
数据库中 D. Auditing is enabled for all privileges. E. Auditing is enabled for certain privileges related to database security. 审计
数据库安全的权限 Answer: CE 参考:http://blog.csdn.net/rlhua/article/details/12292365 如果
数据库是使用Database Configuration Assistant (DBCA) 创建的,默认情况下,audit_trail参数设置为DB。 当AUDIT_TRAIL设置为DB时,默认的行为是将审计线索记录到
数据库的AUD$表中。(C正确) 默认审计 在Oracle Database 11g中启用审计时,将默认审计那些对安全性非常重要的特定权限和语句。(E正确) 系统将针对所有
用户,按成功、失败以及访问来审计上面列出的这些权限和语句。 148.Which dependent object will get invalidated even if it is not affected by the table redefinition? B. triggers 触发器关联的是原表,在线重义后,新表上是没有这个触发器的。 synonyms可以想象想快捷方式,只要有同名表就可以用,不管是重定义还是重建的。 packages与views都是
名称与结构依赖,只要新表中的相关列,就不受影响。 149.You perform a backup using the following BACKUP command: RMAN> BACKUP AS COMPRESSED BACKUPSET DATABASE; Which statement is true of this command? C. Using this command to create backups minimizes the bandwidth consumed 150.You have enabled backup optimization in RMAN. You issue the following RMAN command to configure a redundancy-based retention policy: CONFIGURE RETENTION POLICY TO REDUNDANCY 3; Which statement is true? B. Backup optimization is performed,but RMAN considers the redundancy-based retention policy when it determines which datafiles should be backed up 151.Which statements about the MEMORY_TARGET initialization parameter are true? (Choose all that apply.) A. MEMORY_TARGET can be increased up to the value of MEMORY_MAX_TARGET,if MEMORY_MAX_TARGET is set to a value greater than zero B. MEMORY_MAX_TARGET defaults to a value of zero if MEMORY_TARGET is not set C. MEMORY_TARGET represents the total amount of memory that can be allocated to SGA and PGA memory structures. 152.You are performing incomplete recovery using RMAN. You execute the following RUN block: RUN { SET UNTIL SCN 1107600; RESTORE DATABASE; RECOVER DATABASE; } Which statement is true about the result? B.RMAN restores all datafiles needed to restore the database through SCN 1107599 and applies the redo logs necessary to recover the database through SCN 1107599. RMAN还原所有的数据
文件需要去还原
数据库通过SCN 1107599;应用redo logs必须的去恢复
数据库通过SCN 1107599 通过以上,还原恢复到指定的SCN。 执行时间点恢复 可以通过以下步骤执行服务器管理的时间点恢复。
数据库必须处于ARCHIVELOG模式。 1.确定还原目标。这可以是日期和时间、SCN、还原点或日志序列号。例如,如果你知道某些
错误事务处理是在昨天下午3:00 提交的,则可以选择昨天下午2:59 作为目标还原点时间。 2.设置国家语言
支持(NLS) 操作系统环境变量,确保为RMAN 提供的时间常量的格式是正确的。以下是一些示例设置: $ export NLS_LANG = american_america.us7ascii $ export NLS_DATE_FORMAT = "yyyy-mm-dd:hh24:mi:ss" 3.装载
数据库。如果
数据库已打开,则必须先将其
关闭,如本例所示: RMAN> shutdown immediate RMAN> startup mount 4.创建一个RUN块并运行该块。RECOVER和RESTORE命令应位于同一个RUN块中,这样UNTIL设置可以同时应用于两者。例如,如果选择恢复到特定SCN,则RESTORE命令需要知道该值,以便可以从足够早的备份(即该SCN 之前的备份)还原
文件。 以下是RUN块的一个示例: RUN { SET UNTIL TIME '2007-08-14:21:59:00'; RESTORE DATABASE; RECOVER DATABASE; } 5.打开
数据库进行读/写操作时,会立即完成刚刚执行的还原。因此,先先在READ ONLY模式下打开
数据库并查看某些数据,检查恢复操作是否符合预期结果。 RMAN>
sql 'ALTER DATABASE OPEN READ ONLY'; 6.如果对恢复结果感到满意,则使用RESETLOGS选项打开
数据库,如下所示: RMAN> ALTER DATABASE OPEN RESETLOGS; 153.You are managing an ASM instance. You prev
IoUsly 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? C. ALTER DISKGROUP dg1 UNDROP DISKS; 154.A database is running in ARCHIVELOG mode and regular backups are performed. A user receives the following error message: Which is the recommended sequence of operations you need to perform for the query successfully? C. Restart the database in MOUNT mode,restore the damaged datafile,recover the datafile and then open the database with resetlogs. 155.Observe the structure of the table employees: The table contains 8475 records. One of the employees wants to know the names of all employees of the company. For this,he fires the following query: SELECT * FROM EMPLOYEES ORDER BY emp_fname; Since the operation performed on executing the query cannot fit into memory,it requires disk space to complete the operation. Which of the following types of segments will Oracle allocate to complete the operation and to provide the
required result? B. Temporary segment 临时段 Temporary Segments When processing a query,Oracle Database often requires temporary workspace for intermediate stages of
sql statement execution. Typical operations that may require atemporary segment include sorting,hashing,and merging bitmaps. While creating an index,Oracle Database also places index segments into temporary segments and then converts them into permanent segments when the index is complete. Oracle Database does not create a temporary segment if an operation can be performed in memory. However,if memory use is not possible,then the database automatically allocates a temporary segment on disk。 156.What is the effect of increasing the value of the ASM_POWER_LIMIT parameter? D. The rebalancing operation in an ASM instance completes more quickly,but can result in higher I/O overhead Answer: D 157.The DB_BLOCK_CHECKING initialization parameter is set to OFF. Which block checking would be performed? DB_BLOCK_CHECKING 初始化参数为OFF ,块检查能够运行 E. The Oracle database will perform block checking for the data blocks in the SYSTEM tablespace only Answer: E 158.You create two resource plans,one for data warehouse loading jobs at night and the other for application jobs at day time. You want the resource plans to activate automatically so that the resource allocation is optimum最适宜的 as desired 渴望的 by the activity. How would you achieve this? 你创建两个资源计划,一个为
数据库仓库在夜里加载jobs 另外一个在白天应用jobs 。 你希望资源计划
自动激活 资源分配 B. Implement Scheduler windows 执行调度窗口 调度程序可以在调度程序窗口范围内
自动更改资源管理器计划。如果不希望使用
自动切换,则取消选中默认的“Automatic Plan Switching Enabled(已启用
自动计划切换)”复选框。即实现调度窗口来实现
自动切换。选B. 159.Which package provides API's for the
sql Tuning Advisor? C. DBMS_
sqlTUNE 160.Which two statements are true about the duplexing双工 of the backups taken by RMAN? (Choose two.) B. It is not supported for backup operations that produce image copies D. Duplex backups can be performed to either disk or tape,but cannot be performed on tape and disk simultaneously Configuring Backup Duplexing You can use the CONFIGURE ... BACKUP COPIES command to specify how many copies of each backup piece should be created on the specified device type for the specified type of file. This type of backup is known as a duplexed backup set. The CONFIGURE settings for duplexing only affect backups of data files,control files,and archived logs into backup sets,and do not affect image copies. Note: A control file autobackup is never duplexed. RMAN can duplex backups to either disk or tape,but cannot duplex backups to tape and disk simultaneously. When backing up to tape,ensure that the number of copies does not exceed the number of available tape devices. The following examples show possible duplexing configurations: # Makes 2 disk copies of each data file and control file backup set # (autobackups excluded) CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 2; # Makes 3 copies of every archived redo log backup to tape CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE sbt TO 3; To return a BACKUP COPIES configuration to its default value,run the same CONFIGURE command with the CLEAR option,as in the following example: CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE sbt CLEAR; By default,CONFIGURE ... BACKUP COPIES is set to 1 for each device type. Note: If you do not want to create a persistent copies configuration,then you can specify copies with the BACKUP COPIES and the SET BACKUP COPIES commands. 161.You are using a recovery catalog to maintain Recovery Manager (RMAN) backup information for your production database. You have registered your production database and are performing regular backups. Because of a new requirement you have added a few new tablespaces to your production database and you want them to be included in backups. Identify two options for completing this task. (Choose two.) C. Syncronizing the recovery catalog with the target database control file D. Performing a fresh backup of the target database to include the new data files in the catalog database Answer: CD 162.View the Exhibit to examine the output produced by the following query at three different times since the database instance started and has undergone workloads of different capacities:
sql> SELECT substr(component,10) COMP,current_size CS,user_specified_size US FROM v$memory_dynamic_components WHERE current_size!=0; D. The database instance has the MEMORY_TARGET value set to a nonzero value. Answer: D 动态
性能视图V$MEMORY_DYNAMIC_COMPONENTS
显示所有动态优化的内存组件的当前大小,其中
包括SGA 和实例PGA 的总大小。 三次启动的SGA的各个组件大小都一样,是动态变化的,PGA也是动态变化的,所以此
数据库是处于
自动内存管理即AMM,也即是说MEMORY_TARGET设定为非零值 163.View the Exhibit to observe the error. ORA-0
4031 You receive this error regularly and have to shut down the database instance to overcome the error. What can the solution be to reduce the chance of this error in future,when implemented? 减少出错的机会 D. automatic memory management Answer: D 异常包含的消息:[
4031] ORA-0
4031: unable to allocate 3896 bytes of shared memory ("shared pool","Select VOUCHERTYPEID,APPTYPE...","sga heap(1,0)","kglsim object batch")
解决办法: 用如下命令
修改SGA_MAX_SIZE与SGA_TARGET的值,将大小从1G调整为5G,
数据库正常。
sql> alter system set sga_max_size=5G scope=spfile;
sql> alter system set sga_target=5G scope=spfile; 164.View the Exhibit to examine the details for an incident. Which statement is true regarding the status of the incident? D. The data collection for the incident is complete and the incident can be packaged and sent to Oracle Support. Answer: D 165.View the Exhibit exhibit1. C. Create extended statistics for the CUST_STATE_PROVINCE and CUSTOMERS_ 观看exhibit1图表 在客户OBE表中,客户州省的值是“加利福利亚”, 国家的ID是“美国”。 查看exhibit2图表, 检查命令和
查询计划。优化器可以感测8行而不 是29行,这是实际的表中的行数。你能做些什么使优化器检测实际的选择度? C.为客CUST_STATE_PROVINC和CUSTOMERS_OBE 列创建扩展
统计。 Managing Extended Statistics 在11g中,dbms_stats package提供了组合列的
统计信息的收集,如果在where条件中使用了组合列进行
查询,则优化器将会得到更准确的
统计信息,进而
输出执行计划时,可以
输出更接近与真实数据的
统计结果,11g的Extended Statistics包含了组合列与表达式
统计信息的收集,表过式
统计信息收集主要是针对
函数索引字段,下面就组合列
统计信息的收集做一下测试: 166.Exhibit: View the Exhibit and examine the output. You executed the following command to enable Flashback Data Archive on the EXCHANGE_RATE table: ALTER TABLE exchange_rate FLASHBACK ARCHIVE; What is the outcome of this command? C. The command generates an error because no Flashback Archive name is specified and there is no default Flashback Archive. http://blog.itpub.net/17013648/viewspace-1308519/ --1. 首先创建一个表空间用于存储闪回数据归档 sys@TEST1107>create tablespace fla_tbs1 2 datafile'/u01/app/oracle/oradata/test1107/fla_tbs01.dbf'size 10M; Tablespace created. --2. 创建闪回数据归档 sys@TEST1107>create flashback archive fla1 tablespace fla_tbs1 quota 10M retention 1 year; Flashback archive created. --3.
查询有哪些闪回数据归档以及其状态。 sys@TEST1107>select FLASHBACK_ARCHIVE_NAME,STATUS from DBA_FLASHBACK_ARCHIVE FLASHBACK_ARCHIVE_NAME STATUS ------------------------------------- FLA1 --4. 对scott.dept表启用闪回数据归档,报错,因为没有指定默认闪回归档。 sys@TEST1107>alter table scott.dept flashback archive; alter table scott.dept flashback archive * ERROR at line 1: ORA-55608:Default Flashback Archive does not exist --5.将FLA1指定为默认闪回数据归档。 sys@TEST1107>alter flashback archive FLA1 set default; Flashback archive altered. --6.
查询,此时须注意,status栏位下面的有DEFAULT的状态。 sys@TEST1107>select FLASHBACK_ARCHIVE_NAME,STATUS from DBA_FLASHBACK_ARCHIVE; FLASHBACK_ARCHIVE_NAME STATUS ------------------------------------- FLA1 DEFAULT --7.对表启用闪回数据归档,成功。 sys@TEST1107>alter table scott.dept flashback archive; Table altered. --对于题中的
显示,FLA1的状态栏位为空值,即没有指定FLA1为默认的闪回数据归档,所以,此题正确答案为D. --B答案:这里没有说闪回数据归档被创建在哪个表空间,可以根据DBA_FLASHBACK_ARCHIVE_TS;来
查询,此处没有提供。 sys@TEST0924>select*from DBA_FLASHBACK_ARCHIVE_TS; FLASHBACK_ARCHIVE_NAME FLASHBACK_ARCHIVE#TABLESPACE_NAME QUOTA_IN_MB ---------------------------------------------------------------------------------------- FLA1 1 FLA_TBS1 10 Answer: C 167.View the Exhibits exhibit1 and exhibit2. Both the processes use PROG_1 as the job template that is already available. The time taken by the jobs are recorded in the TEST_LOG table. While comparing the time taken to create the jobs,the process in exhibit1 takes less time than the process in exhibit2. What is the reason for this? 查看图表exhibit1和exhibit2。 这两个进程都使用 PROG_1作为可用的作业模板。 作业所花的时间记录在测试日志表上。比较创建作业所花费的时间, exhibit1表的进程比exhibit2的进程花费较少的时间。这是什么原因呢? 从Exhibit #1中job_style=>'lightweight'可知,此作业是轻量型作业 C. 它创建较少的作业元数据 168.Exhibit: View the Exhibit to examine a portion of the output from the VALIDATE DATABASE command. Which statement is true about the block corruption detected by the command? 检查validate database
数据库的
输出 关于通过命令检测到的坏块描述正确的是: C. The failure is logged into the Automatic Diagnostic Repository (ADR). 说明C正确。 失败记录到ADR中。 DATABASE Validates the database. RMAN validates all data files and control files. If the database is currently using a server parameter file,then RMAN validates the server parameter file. Note: The online redo log files and temp files are not validated. 169.Exhibit #1: View the Exhibit exhibit1 to observe the maintenance window property. View the Exhibit exhibit2 to examine the output of the query. Which two statements describe the conclusions? (Choose two.) A. RESOURCE_PERCENTAGE should be increased. B. The repeat time for the window should be decreased. C. RESOURCE_PERCENTAGE should be decreased. D. The window duration should be increased. Answer: AD 图1,观察维护窗口
属性;图2
查询的
输出 (Choose two.)哪两句描述结论? A. RESOURCE_PERCENTAGEshould be increased.资源百分比应该
增加 D. The window durationshould be increased.窗口期限应该
增加 170.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: FG 答案解析: ASM
支持数据
文件、日志
文件、控制
文件、归档日志、Recovery Manager (RMAN) 备份集及其它Oracle DB
文件类型。ASM 还
支持RAC,这样就不再需要集群逻辑卷管理器或集群
文件系统。 FG,为二进制
文件,不是
数据库文件 171.After executing the command alter diskgroup disk group2 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? C. The drop disk operation is complete and you cannot run the undrop disk command. Answer: C 执行alter diskgroupdisk group2 drop disk dg2a之后,你从ASM实例中执行select group_number,count(*) from v$asm_operation; 从v$asm_operation
查询返回0行,含义是什么? C. The drop diskoperation is complete and you cannot run the undrop disk command. Drop磁盘操作已经完成,你不能运行undrop磁盘命令。 172.What is the net effect of the following command? alter diskgroup dgroup1 drop disk abc; C. The disk group will be automatically rebalanced during the drop operation. Once the rebalancing is complete,the disk will be dropped. 173.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 174.What Oracle process runs when the database is in ARCHIVELOG mode but not when it is in NOARCHIVELOG mode? C. ARCH 归档进程
名称 175.You are peer reviewing同业互查 a fellow DBAs backup plan for his NOARCHIVELOG mode database,as shown here: Put the tablespaces in backup mode. Back up the datafiles for all tablespaces. Take the tablespaces out of backup mode. Back up all archived redo logs. Your colleague同事 asks for you to comment on his plan. Which response would be correct? B. The plan needs to be modified to allow for an archive-log switch after step 3. 通过执行alter system switch logfile 执行一下日志切换和归档, 将日志记录进去 176.Which of the following statements is true when the database is in ARCHIVELOG mode and tablespaces are in hot backup mode? D. The datafile headers are not updated during the backup. 177.When you create a backup control file,where is the resulting file written to? E. To the directory and filename you specify in the command Answer: E 创建控制
文件备份,写入到命令指示的目录和
文件中 178.If a log file becomes corrupted,it may cause the database to stall停止. How would you correct such a situation? C. Use the alter database clear logfile command to clear the log file. 清除日志
文件 179.You have lost datafiles 1 and 3 from your database,and the database has crashed. In what order should you perform the following steps to recover your database? 1. Take the datafiles that were lost offline. 2. startup mount the database 3. Issue the alter database open command. 4. Restore the datafiles that were lost 5. Recover the datafiles with the recover datafile command. 6. Bring the datafiles back online. 7. Recover the database with the recover database command. B. 2,3 丢失数据
文件,
数据库崩溃,恢复
数据库的步骤 以mount启动
数据库 , 还原丢失的数据
文件, 通过恢复命令恢复数据
文件 ,打开
数据库 180.Which command is used to open the database after an incomplete recovery? C. alter database open resetlogs 不完全恢复
数据库, 执行哪个命令 181.Your database has a backup that was taken yesterday (Tuesday) between 13:00 and 15:00 hours. 下午1点到3点备份 This is the only backup you have.唯一的备份 You have lost all the archived redo logs generated since the prev
IoUs Monday,周一的归档联机日志丢失, but you have archived redo logs available from the prev
IoUs Sunday and earlier. 周日以前和更早的有You now need to restore your backup due to database loss.
数据库丢失恢复To which point can you restore your database恢复的时间节点 E. The database is not recoverable. Answer: E 你的
数据库有一个昨日 (星期二) 13:00 至 15:00 小时进行的备份。这是唯一的备份。您已经失去了从过去的周一以来产生的所有 的归档重做日志,但你有过去的周日和更早的归档重做日志可以利用。 由于
数据库丢失你现在需要恢复您的 备份。 哪一点你可以恢复你的
数据库? E. 该
数据库是无法恢复的 The database is not recoverable. You would need all the archived redo logs generated during the backup on Tuesday,at least,to restore the database after that backup. The online redo logs are very unlikely to have all the redo that would be
required. 该
数据库是无法恢复的。您将需要在周二备份过程中产生的所有的 归档重做日志,至少在备份后还原
数据库。联机重做日志是不太可能有所有需要的重做。欲了解更多信 息,请参见第3章“ 执行Oracle
用户管理的
数据库收回。” 182.Which of the following files cannot be backed up by RMAN? (Choose all that apply.) C. Online redo logs D. Database pfiles 183.Which of the following RMAN structures can data from a datafile span? B. RMAN backup-set pieces within a given backup set 以下哪个 RMAN 结构记录着数据文 件的范围? B. 给定备份集中的 RMAN 备份集块 184.Which RMAN backup command is used to create the block-change tracking file? C. alter database enable block change tracking using file,/ora01/opt/ block_change_tracking.fil 块改变跟踪 185.A shoot-out has erupted between your MS development teams using .NET and your Linux development teams using Java. Knowing that your database is in danger,which command would you use to back up your NOARCHIVELOG mode database using RMAN with compression? 使用RMAN 压缩备份非归档模式
数据库 C. backup as compressed backupset database; 一 场冲突已经在关于使用.NET 的 MS 开发团队和使用 Java 的 Linux 开发团队之间爆发。知道你的
数据库处于危险之中,你会用哪个命令使用 压缩的 RMAN 来备份您的非归档记录模式的
数据库? C. 备份压缩的备份集
数据库; 185.A shoot-out has erupted between your MS development teams using .NET and your Linux development teams using Java. Knowing that your database is in danger,which command would you use to back up your NOARCHIVELOG mode database using RMAN with compression? A. backup database all B. backup compressed database C. backup as compressed backupset database; D. backup as compressed backup database plus archivelog all; E. backup as compressed backupset database plus compress archivelog all; Answer: C 答案解析: 参考:http://docs.oracle.com/cd/E11882_01/backup.112/e10642/rcmbckba.htm#BRADV8138 在noarchivelog模式下不能备份。
sql> archive log list Database log mode No Archive Mode Automatic archival Disabled Archive destination USE_DB_RECOVERY_FILE_DEST Oldest online log sequence 8 Current log sequence 10
sql> ! [oracle@node2 ~]$ rman target / Recovery Manager: Release 11.2.0.4.0 - Production on Sun Feb 23 11:45:09 2014 Copyright (c) 1982,2011,Oracle and/or its affiliates. All rights reserved. connected to target database: TEST0221 (DBID=3883475966) RMAN> backup as compressed backupset database; Starting backup at 23-FEB-14 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=33 device type=DISK channel ORA_DISK_1: starting compressed full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set RMAN-03009: failure of backup command on ORA_DISK_1 channel at 02/23/2014 11:46:01 ORA-19602: cannot backup or copy active file in NOARCHIVELOG mode continuing other job steps,job
Failed will not be re-run channel ORA_DISK_1: starting compressed full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set including current control file in backup set including current SPFILE in backup set channel ORA_DISK_1: starting piece 1 at 23-FEB-14 channel ORA_DISK_1: finished piece 1 at 23-FEB-14 piece handle=/u01/app/oracle/fast_recovery_area/TEST0221/backupset/2014_02_23/o1_mf_ncsnf_TAG20140223T114559_9jlvqv10_.bkp tag=TAG20140223T114559 comment=NONE channel ORA_DISK_1: backup set complete,elapsed time: 00:00:04 RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03009: failure of backup command on ORA_DISK_1 channel at 02/23/2014 11:46:01 ORA-19602: cannot backup or copy active file in NOARCHIVELOG mode RMAN> ----------------------------------------------------------------------------------------
sql> archive log list; Database log mode Archive Mode Automatic archival Enabled Archive destination USE_DB_RECOVERY_FILE_DEST Oldest online log sequence 8 Next log sequence to archive 10 Current log sequence 10
sql> ! [oracle@node2 ~]$ rman target / Recovery Manager: Release 11.2.0.4.0 - Production on Sun Feb 23 11:49:43 2014 Copyright (c) 1982,Oracle and/or its affiliates. All rights reserved. connected to target database: TEST0221 (DBID=3883475966) RMAN> backup as compressed backupset database; Starting backup at 23-FEB-14 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=26 device type=DISK channel ORA_DISK_1: starting compressed full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set input datafile file number=00001 name=/u01/app/oracle/oradata/test0221/system01.dbf input datafile file number=00002 name=/u01/app/oracle/oradata/test0221/sysaux01.dbf input datafile file number=00005 name=/u01/app/oracle/oradata/test0221/example01.dbf input datafile file number=00003 name=/u01/app/oracle/oradata/test0221/undotbs01.dbf input datafile file number=00004 name=/u01/app/oracle/oradata/test0221/users01.dbf channel ORA_DISK_1: starting piece 1 at 23-FEB-14 channel ORA_DISK_1: finished piece 1 at 23-FEB-14 piece handle=/u01/app/oracle/fast_recovery_area/TEST0221/backupset/2014_02_23/o1_mf_nnndf_TAG20140223T114959_9jlvz90q_.bkp tag=TAG20140223T114959 comment=NONE channel ORA_DISK_1: backup set complete,elapsed time: 00:03:36 channel ORA_DISK_1: starting compressed full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set including current control file in backup set including current SPFILE in backup set channel ORA_DISK_1: starting piece 1 at 23-FEB-14 channel ORA_DISK_1: finished piece 1 at 23-FEB-14 piece handle=/u01/app/oracle/fast_recovery_area/TEST0221/backupset/2014_02_23/o1_mf_ncsnf_TAG20140223T114959_9jlw64w0_.bkp tag=TAG20140223T114959 comment=NONE channel ORA_DISK_1: backup set complete,elapsed time: 00:00:04 Finished backup at 23-FEB-14 RMAN> ------------------------------------------------------------------------------------ Making Compressed Backups For any use of the BACKUP command that creates backup sets,you can take advantage of RMAN support for binary compression of backup sets. Specify theAS COMPRESSED BACKUPSET option to the BACKUP command. RMAN compresses the backup set contents before writing them to disk. The details of which binary compression level is used are automatically recorded in the backup set. There is no need to explicitly mention the type of compression used or how to decompress the backup set in the recovery operation. Example 9-7 backs up the entire database and archived logs to the configured default backup destination (disk or tape),producing compressed backup sets. Example 9-7 Making Compressed Backups BACKUP AS COMPRESSED BACKUPSET DATABASE PLUS ARCHIVELOG; Binary compression creates some performance overhead during backup and restore operations. Binary compression consumes
cpu resources,so compressed backups should not be scheduled when
cpu usage is high. However,the following circumstances may warrant paying the performance penalty: You are using disk-based backups when disk space in your fast recovery area or other disk-based backup destination is limited. You are performing your backups to some device over a network when reduced network bandwidth is more important than
cpu usage. You are using some archival backup media such as CD or DVD,where reducing backup sizes saves on media costs and archival storage. 186.What is the purpose of the RMAN recovery catalog? (Choose all that apply.) A. Make backups faster B. Store RMAN
Metadata C. Store RMAN scripts D. Provide the ability to do centralized backup reporting. E. Make recovery faster Answer: BCD 187.RMAN provides more granular颗粒的 catalog security through which feature? B. Virtual private catalog 题问:RMAN提供更细化的目录安全
功能是通过哪个特性? virtual private catalog A subset of the
Metadata in a base recovery catalog to which a database user is granted access. The owner of a base recovery catalog can grant or revoke restricted access to the recovery catalog to other database users. Each restricted user has full read/write access to his own virtual private catalog。 virtual private catalog 虚拟专用目录(VPC)使用此
功能可以合并RMAN 资料档案库并保持职责分离,这是一项基本安全要求。 RMAN 目录已被增强,可用于创建
数据库组和
用户组的虚拟专用RMAN 目录。该目录的所有者将创建基本目录并为虚拟目录的所有者授予RECOVERY_CATALOG_OWNER权限。目录的所有者可为虚拟目录的所有者授予访问已
注册数据库的权限或REGISTER权限。然后,虚拟目录所有者可连接到特定目标的目录,或者
注册一个目标
数据库。完成配置后,VPC 所有者可像使用标准基本目录一样使用虚拟专用目录。 作为目录所有者,你可以访问该目录中所有已
注册的
数据库信息。你可以列出使用
sql*Plus 命令
注册的所有
数据库: SELECT DISTINCT db_name FROM DBINC; 作为虚拟目录所有者,你只能查看授予了你访问权限的
数据库。 注:如果目录所有者未被授予对目标
数据库的SYSDBA或SYSOPER权限,则无法执行大多数RMAN 操作。 188.You can back up the RMAN recovery catalog with RMAN. A. True 189.What RMAN command must you use before you can back up a database using the recovery catalog? E. register database Answer: E 190.You have control-file autobackups enabled. When starting your database from
sql*Plus,you receive the following error message:
sql> startup ORA-01078: failure in processing system parameters LRM-00109: could not open parameter file,C:\ORACLE\PRODUCT\11.1.0\DB_1\DATABASE\INITORCL.ORA Using RMAN,how would you respond to this error? C. Issue the startup nomount command and then issue the restore spfile from autobackup command from the RMAN prompt. 恢复参数
文件 191.While working on a data problem,Curt,Bill,Ben,Mike,and Matt introduced a vast amount of corrupted data into the database. Pablo has discovered this problem and he needs you to recover the database to the point in time prior to the introduction of the corruption. The logical corruption was introduced at 6:30 p.m. on September 6,2008. Which of the following would be the correct commands to use to restore the database to a point in time before the orruption? C. restore database until time '06-SEP-2008 18:29:55'); recover database until time '06-SEP-2008 18:29:55'); alter database open resetlogs; 在2008年9月6号 下午6:30 出现
错误 还原
数据库到那个时间点 192.What is the purpose of the until change option of the restore command? A. It allows you to select the SCN that you want to restore to. until选项的作用 193.What is the purpose of the recover command? (Choose all that apply.) A. Recover database datafiles from physical disk backup sets. B. Recover
required incremental backups from physical disk backup sets. C. Recover
required archived redo logs from physical disk backup sets. D. Apply incremental backups to recover the database. E. Apply archived redo logs to recover the database. Answer: BCDE Prerequisites All redo or incremental changes
required for the recovery must exist on disk or in SBT. If RMAN needs to restore incremental backups or archived redo log files during recovery,then you must either have automatic channels configured or manually allocate channels of the same type that created these backups. 194.What is an obsolete过时的 backup set? B. A backup that has exceeded超过 the retention保留 criteria标准 and is no longer needed不在需要 195.What is the purpose of the list expired backup command? 列出过期的备份:RMAN> list expired backup; C. Lists all backups that are missing associated关联的 physical backup set pieces 物理备份集块 当备份
文件被os
删除或在os中找不到后,因为在控制
文件中对应信息还在 cross check后会被标识为expired EXPIRED Displays backup sets,proxy copies,and image copies marked in the repository asEXPIRED,which means they were not found. See Table 2-9,"List of Backup Sets (for data file backup sets)" for a description of the output. To ensure that LIST EXPIRED shows up-to-date output,use a CROSSCHECK command periodically. When you use a CROSSCHECK command,RMAN searches disk and tape for backups and copies recorded in the repository. If it does not find them,then it updates their repository records to status EXPIRED. 196.What is the purpose of the catalog command? C. To create
Metadata in the control file and the recovery catalog related to backup set pieces 目录命令的目的是什么? C. 创建与备份集片相关的控制
文件和恢复目录中的元数据 元数据的定义为“有关数据的结构数据”, 例如某个
数据库中的表和视图的个数及
名称,某个表或者视图中 列的个数以及每一列的
名称、数据类型、长度、精度、描述等,某个表上定义的约束,某个表上定义的索引 以及主键/外键的信息 在9i时代,如果在控制
文件或者catalog
数据库中的备份信息被覆盖或者清除,那么即使所有的备份
文件都在,rman也无法简单的利用这些
文件来做恢复了,必须得用些特别的
方法才能办到,比如以前很多牛人写的使用dbms_backup_restore包从备份片中释放出数据
文件,然后再使用手工方式做恢复。 但是实际上,oracle完全可以将恢复时需要的一些信息保存在备份
文件的
文件头中,如果控制
文件或者catalog
数据库中的信息丢失,再扫描一遍
文件头,取出这些信息就可以了。10g中就是这么实现的,扫描这些
文件头的工作就是由这个新的catalog命令来实现的。注意这是10g rman的一个命令,虽然和以前的catalog database的名字长得一样,可不是同一个东西。 catalog命令可以用来扫描备份片,
文件拷贝(datafile or controlfile copy),也可以用来扫描归档日志,所以,只要你的备份还在,归档还在,即使catalog database崩溃,控制
文件重建,照样可以用这些备份来做恢复。 扫描备份片 CATALOG BACKUPPIECE ‘?/oradata/01dmsbj4_1_1.bcp’; 扫描归档日志 CATALOG ARCHIVELOG ‘?/oradata/archive1_30.dbf’,‘?/oradata/archive1_31.dbf’; 扫描数据
文件拷贝,并且将其做为增量备份的level 0 CATALOG DATAFILECOPY ‘?/oradata/users01.bak’ LEVEL 0; 扫描控制
文件拷贝 CATALOG CONTROLFILECOPY ‘controlfilecopy.ctl’ 扫描整个目录,如果备份片或者归档日志
文件太多,可以放到一个目录中,一次性扫描就行 CATALOG START WITH ‘/tmp/arch_logs’; 扫描闪回恢复区 CATALOG RECOVERY AREA NOPROMPT; 这里需要注意将备份的log和备份
文件一起保存下来,不然就不知道哪些
文件属于哪个备份集,恢复的时候就要多浪费些时间啦。但是注意这些命令是有限制的,其中的一个限制是不能
注册备份
文件到不同的
数据库: You cannot use CATALOG to catalog a file that belongs to a different database. 也就是说你至少还需要原
数据库的控制
文件。 否则就会出现类似如下的
错误: $ rman target / Recovery Manager: Release 10.2.0.1.0 - Production on Thu May 22 01:02:56 2008 Copyright (c) 1982,2005,Oracle. All rights reserved. connected to target database (not started) RMAN> set dbid=1490303982 executing command: SET DBID RMAN> startup mount; Oracle instance started database mounted Total System Global Area 285212672 bytes Fixed Size 1218992 bytes Variable Size 92276304 bytes Database Buffers 188743680 bytes Redo Buffers 2973696 bytes RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03002: failure of startup command at 05/22/2008 01:03:08 RMAN-06189: current DBID 1490303982 does not match target mounted database (1492784050) 当然我们可以通过先
修改一个恢复
数据库的DBID,然后再来
注册这个备份集。如何
修改DBID可以参考 197.Which of the following commands will fail? A. report schema; B. report need backup; C. report need backup days 3; D. report user; E. report obsolete; Answer: D RMAN的report命令用于判断
数据库的当前可恢复状态和提供
数据库备份的特定信息。 1. 报告最近没有被备份的数据
文件 查看最近3天没有备份过的表空间,如: rman>report need backup days = 3; 根据需要应用的增量备份数
生成报告,如: rman>report need backup incremental = 3; 2. 报告备份冗余或恢复窗口 rman>report need backup redundancy = 2; rman>report need backup recovery window of 2 days; 3. 报告数据
文件的不可恢复操作 rman>report unrecoveable; 4. 报告
数据库模式 模式指的是
数据库的物理结构。模式
包括数据
文件名、数据
文件号、为这些数据
文件指派的表空间、数据
文件大小、以及数据
文件是否含有回滚段。 rman>report schema; 5. 报告丢弃的备份 如备份时使用了保存策略,备份有可能会被
标记为丢弃状态(OBSOLETE)。此时执行report obsolete就可查看到丢弃的备份记录 198.What are the two different types of database duplication复制 副本? (Choose two.) A. Active 主动 B. Passive C. Online D. Backup-based 基于备份的 E. Failure driven Answer: AD 199.When youre performing a tablespace point-in-time recovery,which tablespaces will always be restored to the auxiliary instance? (Choose all that apply.) 表空间时间点恢复 A. The SYSTEM tablespace. B. The UNDO tablespace RMAN的
自动表空间按时间点恢复(TSPITR)能让你将
数据库中的一个或多个表空间
快速恢复到之前的某个时间点,而不会影响
数据库中的其它表空间和对象。 为了有效地使用表空间按时间点恢复(TSPITR),需要理解你需要
解决的问题是什么,使用TSPITR的主要原因是什么,在执行TSPITR时RMAN将会执行那些操作,何时以及如何使用TSPITR,使用TSPITR有那些限制 200.Which operation requires that you create an auxiliary instance manually before executing the operation? (Choose all that apply.) A. Backup-based database duplication. 基于备份的副本
数据库 B. Active database duplication. 活动
数据库复制
数据库复制 201.Examine the following PL/
sql block: SET SERVEROUTPUT ON SET LONG 10000 ECLARE report clob; BEGIN report := DBMS_SPM.EVOLVE_
sql_PLAN_BASELINE(); DBMS_OUTPUT.PUT_LINE(report); END; Which statement describes the effect of the execution of the above PL/
sql block? D. The nonaccepted plans in the
sql Management Base are verified with the existing plan baselines. Answer: D EVOLVE_
sql_PLAN_BASELINE Function This function evolves
sql plan baselines associated with one or more
sql statements. A
sql plan baseline is evolved when one or more of its non-accepted plans is changed to an accepted plan or plans. If interrogated by the user (parameter verify = 'YES'),the execution performance of each non-accepted plan is compared against the performance of a plan chosen from the associated
sql plan baseline. If the non-accepted plan performance is found to be better than
sql plan baseline performance,the non-accepted plan is changed to an accepted plan provided such action is permitted by the user (parameter commit = 'YES'). The second form of the function employs a plan list format.