单选题User A issues the command: LOCK TABLES pets READ; Which command can User B execute against the pets table?（）A UPDATE pets…B SELECT….FROM petsC INSERT INTO pets…D ALTER TABLE pets…

第1题：

You are responsible for a data warehouse application that uses records from an external table to update one of the dimension tables periodically. The records in the external table may contain data for new rows in the dimension table， or for updates to its existing rows. Which type of SQL command would you use to transfer the data from the external table to the dimension table as efficiently as possible？（）

• A、MERGE
• B、SELECT …CROSS JOIN
• C、INSERT ALL …SELECT
• D、CREATE VIEW …CONSTRAINT

第2题：

One of the users in the PROD database， Adams， complains that his update on the table， TRANS， is taking an unusually long time to complete. You find that the table gets locked by another database user before Adams starts his transactions， and you are unable to contact the user holding the table lock. As Adams is updating some crucial rows in the table， he should get the highest priority. Which method would you use to overcome this problem？（）

• A、execute the command， ALTER SESSION KILL ..， to kill the blocking session
• B、execute the DBMS_SESSION.KILL_SESSION procedure to kill the blocking session
• C、execute the command， ALTER SYSTEM KILL SESSION ..， to kill the blocking session
• D、execute the command， ALTER SESSION UNLOCK ..， to release the lock for the blocking session
• E、execute the command， ALTER SYSTEM UNLOCK SESSION ..， to release the lock for the blocking session

第3题：

User SCOTT executes the following command on the EMP table but has not issued COMMIT， ROLLBACK， or any data definition language （DDL） command： SQL> SELECT ename FROM emp  2 WHERE job=’CLERK’ FOR UPDATE OF empno；  SCOTT has opened another session to work with the database instance.  Which three operations wouldwait when issued in SCOTT’s second session（）

• A、LOCK TABLE emp IN SHARE MODE；
• B、LOCK TABLE emp IN EXCLUSIVE MODE；
• C、UPDATE emp SET sal=sal*1.2 WHERE job=MANAGER；
• D、INSERT INTO emp（empno，ename） VALUES （1289，’Harry’）；
• E、SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno；

第4题：

User A executes the following command to update the TRANS table）  SQL> UPDATE B.trans SET tr_amt=tr_amt+500 WHERE c_code=’C005’；  Before user A issues a COMMIT or ROLLBACK command， user B executes the following command on the TRANS table：   SQl> ALTER TABLE trans MODIFY （tr_type VARCHAR2 （3））；  What would happen in this scenario？（）

• A、The transaction for user A is rolled back.
• B、The ALTER TABLE command modifies the column successfully.
• C、The ALTER TABLE command fails due to the resource being busy.
• D、The ALTER TABLE command waits until user A ends the transaction.

第5题：

 A user issues a SELECT command against the Oracle database. Which of the following choices describes a step that Oracle will execute in support of this statement?（）

• A、Acquire locks on table queried 
• B、Generate redo for statement 
• C、Fetch data from disk into memory 
• D、Write changes to disk

第6题：

User SCOTT executes the following command on the EMP table but has not issued COMMIT， ROLLBACK，or any data definition language （DDL） command：  SQL> SELECT job FROM emp  2  WHERE job=’CLERK’ FOR UPDATE OF empno;  SCOTT has opened another session to work with the database. Which three operations would wait when issued in SCOTT’s second session？（）

• A、LOCK TABLE emp IN SHARE MODE;
• B、LOCK TABLE emp IN EXCLUSIVE MODE;
• C、DELETE FROM emp WHERE job=’MANAGER’;
• D、INSERT INTO emp（empno，ename） VALUES （1289，’Dick’）;
• E、SELECT job FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno;

第7题：

第8题：

第9题：

第10题：

第11题：

第12题：

第13题：

You execute the following command to audit database activities： SQL> AUDIT DROP ANY TABLE BY scott BY SESSION WHENEVER SUCCESSFUL； What is the effect of this command（）

• A、One audit record is created for every successful DROP TABLE command executed in the session of SCOTT.
• B、One audit record is generated for the session when SCOTT grants the DROP ANY TABLE privilege to otherusers.
• C、One audit record is created for the whole session if user SCOTT successfully drops one or more tables inhis session.
• D、One audit record is created for every session of any other user in which a table owned by SCOTT isdropped successfully.
• E、One audit record is created for every successful DROP TABLE command executed by any user to drop Tables owned by SCOTT

第14题：

The user Sue issues this SQL statement: GRANT SELECT ON sue. EMP TO alice WITH GRANT OPTION; The user Alice issues this SQL statement: GRANT SELECT ON sue. EMP TO reena WITH GRANT OPTION; The user Reena issues this SQL statement: GRANT SELECT ON sue. EMP TO timber; The user Sue issues this SQL statement: REVOKE select on sue. EMP FROM alice; For which users does the revoke command revoke SELECT privileges on the SUE.EMP table?（）

• A、Alice only
• B、Alice and Reena
• C、Alice, Reena, and Timber
• D、Sue, Alice, Reena, and Timber

第15题：

User SCOTT executes the following command on the EMP table but has not issued COMMIT， ROLLBACK， orany data definition language （DDL） command： SQL> SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno； SCOTT has opened another session to work with the database instance.  Which three operations would waitwhen issued in SCOTT’s second session（）

• A、LOCK TABLE emp IN SHARE MODE；
• B、LOCK TABLE emp IN EXCLUSIVE MODE；
• C、UPDATE emp SET sal=sal*1.2 WHERE job=ANAGER？UPDATE emp SET sal=sal*1.2 WHERE job=？ANAGER？
• D、INSERT INTO emp（empno，ename） VALUES （1289，’Harry’）；
• E、SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno

第16题：

The user HR owns the EMP table. The user HR grants privileges to the user SCOTT by using this command：  SQL> GRANT SELECT，INSERT，UPDATE ON emp TO scott WITH GRANT OPTION； The user SCOTT executes this command to grant privileges to the user JIM： SQL> GRANT SELECT，INSERT，UPDATE ON hr.emp TO jim；  Now， the user HR decides to revoke privileges from JIM using this command： SQL> REVOKE SELECT，INSERT，UPDATE ON emp FROM jim； Which statement is true after HR issues the REVOKE command（）

• A、The command fails because SCOTT still has privileges.
• B、The command succeeds and privileges are revoked from JIM.
• C、The command fails because HR cannot revoke the privileges from JIM.
• D、The command succeeds and only HR has the privilege to perform the SELECT， INSERT， and UPDATEoperations on the EMP table.

第17题：

User A issues the command: LOCK TABLES pets READ; Which command can User B execute against the pets table?（）

• A、UPDATE pets…
• B、SELECT….FROM pets
• C、INSERT INTO pets…
• D、ALTER TABLE pets…

第18题：

第19题：

第20题：

第21题：

第22题：

第23题：

第24题：