The instance abnormally terminates because of a power outage. 
Which statement is true about redo log filesduring instance recovery（）

单项选择题Examine the command： SQL> DBMS_STATS.SET_TABLE_PREFS（’SH’， ’CUSTOMERS’， ’PUBLISH’， ’false’）；  Which statementdescribes the effect of the above command（）

A.Automatic statistics collection is stopped for the CUSTOMERS table.
B.Statistics for the CUSTOMERS table are locked and cannot be overwritten.
C.Existing statistics for the CUSTOMERS table become unusable for the query optimizer.
D.Subsequently， statistics gathered on the CUSTOMERS table are stored as pending statistics

单项选择题You are installing Oracle Database 11g on a machine. When you run the installer， the Oracle Universal Installer（OUI） shows the message that says one of the product-specific prerequisite checks has failed：Checking available swap space requirements ...Expected result： 1512MBActual Result： 1018MB Check complete. The overall result of this check is： Failed <<<< Problem： The system does not have therequired swap space. What happens to the installation in this situation（）

A.It can be continued.
B.It resizes the swap space automatically when you proceed further.
C.It can be continued， but the instance cannot be started without increasing the swap space.
D.It shows a message saying one or more prerequisite checks have failed and the installation cannot proceed

单项选择题YouareinstallingOracleDatabase11gonyourserver.DuringtheinstallationOracleUniversalInstaller（OUI） promptsyoutoenterthepathoftheinventorydirectoryandalsopromptsyoutospecifyanoperatingsystemgroupname. Whichstatementistrueinthiscase（）

A.The ORACLE_BASE parameter is not set.
B.The installation is being performed by the root user.
C.The operating system group that will be specified should have root user as its member.
D.The installation is being performed without the "Create Starter Database" option selected.
E.The operating system group that will be specified must have permission to write to the inventory directory

单项选择题You want to create a role to meet these requirements： 1. The role is to be protected from unauthorized usage. 2. The password of the role is not to be embedded in the application source code or stored in a table. method would you use to restrict enabling of such roles（）

A.Create the role with external authentication.
B.Create the role as a secure application role.
C.Create the role as a password-protected role.
D.Create a role and use Fine-Grained Access Control （FGAC） to secure the role

单项选择题Youhaveexecutedthiscommandtochangethesizeofthedatabasebuffercache： SQL>ALTERSYSTEMSETDB_CACHE_SIZE=2516582； Systemaltered.Toverifythechangeinsize，youexecutedthiscommand：SQL>SHOWPARAMETERDB_CACHE_SIZENAMETYPEVALUE ------------------------------------------------db_cache_sizebiginteger4194304 Whyisthevaluesetto4194304andnotto2516582（）

A.Because 4194304 is the granule size
B.Because 4194304 is the standard block size
C.Because 4194304 is the largest nonstandard block size defined in the database
D.Because 4194304 is the total size of data already available in the database buffer cache