[bbk4343]小布-OCP 042全真试题讲解

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[bbk4343]小布-OCP 042全真试题讲解

• 1、You are in the middle of a transaction and very crucial data has been modified.Because of a hardware failure,the instance has shutdown before synchronizing all the database files.

Which two statements are true ? (Choose two.)

• • A.On startup,SMON coordinates instnace recovery.
  • B.On startup,CKPT coordinates instance recovery.
  • C.On startup,use RMAN to perform instance recovery.
  • D.Uncommitted changes will be rolled back after the database is opened.
  • E.On startup,perform media recovery and then instance recovery.
  • F.On startup,all the files will be synchronized and you get both committed and uncommitted data.

instance recovery是用SMON进程自动实现的.instance recovery是不需要DBA干预的.说白了instance recovery是SMON干的活，不属于RMAN的活；RMAN的主要工作时media reovery.

media recovery可以理解为磁盘损坏.RMAN主要是用来做Media Recovery.

• 2、You want the user APP_DBA to administer the Oracle database from a remote machine.APP_DBA is granted the SYSDBA privilgeg to perform administrative tasks on the database.

Which file is used by the Oracle Database server to authenticate APP_DBA?

• • A.control file
  • B.password file
  • C.listener controller file
  • D.control file and password file
• 3、which three statements are true regarding the logical structure of the Oracle database ?(choose three)
  • A.Each segment contains one or more extents.
  • B.Multiple tablespace can share single data file.
  • C. data block is the smallest unit of I/O for datafiles.
  • D.It is possible to have tablespace of different block size in a database.
  • E.Each data block in the database always corresponds to one OS block.
• 4、Which is the memory area that is created when a dedicated server process is started,and contains data and control information for that server process?
  • A.SGA
  • B.PGA
  • C.Shared Pool
  • D.Streams Pool

系统表空间和临时表空间的block size大小是由db_block_size参数指定的，其他的表空间的大小可以由db_block_size参数指定，也可以由其他参数指定.

• 5、You find that the database perfomance degrades while you backup the PROD database using Recovery Manager(RMAN).The PROD database is running in shared server mode.The database instance is currently using 60% of total operating system memory.You suspect the shared pool fragmentatation to be the reason.

Which action would you consider to overcome the perfomance degradation?

• • A.Configure Java Pool to cache the java objects.
  • B.Configure Streams Pool to enable parallel processing.
  • C.Increase Shared Pool Size to cache more PL/SQL objects.
  • D.Increase Database Buffer Cache size to increase cache hits.
  • E.Configure Large Pool to be used by RMAN and shared server.
  • F.Increase the total system global area(SGA) size to increase memory hints.

Shared Server模式下,使用RMAN做备份时，通过增加LARGE POOL SIZE来配合使用，会更加有效；否则RMAN会挤占Shared Pool中的资源，从而降低数据库性能.