单选题To allocate another role to a user, which command is most appropriate?（）A ALTER USER B ALTER DATABASE C ALTER SYSTEM D GRANT

第1题：

User SCOTT wants to back out the transactions on the REGIONS table in his schema. As a DBA, which commands must you execute to enable SCOTT to flash back the transactions?（）

• A、ALTER DATABASE FLASHBACK ON;
• B、GRANT SELECT any transaction TO scott;
• C、GRANT EXECUTE ON dbms_flashback TO scott;
• D、ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;
• E、ALTER TABLESPACE undots1 RETENTION GUARANTEE;
• F、ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (PRIMARY KEY) COLUMNS;

第2题：

Examine the command： SQL> ALTER USER skd ACCOUNT LOCK； Which two statements are true after the command is executed（）

• A、The SKD user cannot log in to the database instance.
• B、The objects owned by the SKD user are not accessible to any user.
• C、The other users can access the objects owned by the SKD user， on which they have access.
• D、The password for the SKD user expires and the user is forced to change the password at the next log in

第3题：

第4题：

You execute the following command in your Certkiller .com production database to change the width of the CUST_NAME column of the CUSTOMERS table： ALTER TABLE customers  MODIFY （cust_nameVARCHAR2 （40）） /  When you execute the command， it displays the following error message：  ERROR at line 1：  ORA-00054： resource busy and acquire with NOWAIT specified  What could be the reason for the error message？（）

• A、The database instance is not available.
• B、The ALTER TABLE command does not have WAIT option
• C、The table or a row in the table is currently locked by another user session.
• D、The database instance is busy processing other user sessions commands.
• E、The CUSTOMERS table has no long running query active at the time when this request is made.
• F、The server process executing the ALTER TABLE command is busy with another command execution

第5题：

Examine the command： SQL> ALTER USER skd ACCOUNT LOCK； Which two statements are true after the command is executed（）

• A、The SKD user cannot log in to the database instance.
• B、The objects owned by the SKD user are not accessible to any user.
• C、The other users can access the objects owned by the SKD user， on which they have access.
• D、The password for the SKD user expires and the user is forced to change the password at the next log in.

第6题：

Which command is used to open the database after an incomplete recovery？（）

• A、 alter database open
• B、 alter database open repairlog
• C、 alter database open resetlogs
• D、 alter database open resetlog
• E、 alter database resetlogs open

第7题：

Which RMAN backup command is used to create the block-change tracking file？（）  

• A、 alter database create block change tracking file
• B、 alter database enable block change file
• C、 alter database enable block change tracking using file ，/ora01/opt/ block_change_tracking.fil
• D、 alter system enable block change tracking using file ’/ora01/opt/block_ change_tracking.fil’
• E、 alter system block change tracking on

第8题：

第9题：

The DBA is defining role for users. Which of the following is not an acceptable method for defining a default role?（）

• A、ALTER USER DEFAULT ROLE ALL
• B、ALTER USER DEFAULT ROLE ALL EXCEPT ROLE_1
• C、ALTER USER DEFAULT ROLE NONE
• D、ALTER USER DEFAULT ROLE NONE EXCEPT ROLE_1

第10题：

You are attempting to clear an unarchived redo log file. In order to manually enact a log switch, which of the following statements is appropriate?（）

• A、ALTER DATABASE 
• B、ALTER SYSTEM 
• C、ALTER USER 
• D、ALTER REDO LOG