所谓LRU页面置换算法，是指（)A．将驻留在主存中的页面随便挑选一页淘汰B．将驻留在主存中的时间最

A. no privileges

B. only the SELECT privilege

C. only the CONNECT privilege

D. all the privileges of a default user

A. No privileges.

B. Only the SELECT privilege.

C. Only the CONNECT privilege.

D. All the privileges of a default user.

ma 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？（）

A. The second user‘s session immediately produces the resource busy error.

B. The second user‘s command executes successfully.

C. The second user‘s session waits for a time period before producing the resource busy error.

D. A deadlock is created.

; 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

;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

A．CREATE LOGIN

B． CREATE USER

C． ADD LOGIN

D． ADD USER

A.UPDATE pets…

B.SELECT….FROM pets

C.INSERT INTO pets…

D.ALTER TABLE pets…

Scott issues the SQL statements:CREATE TABLE dept(deptno NUMBER(2),dname VARCHAR2(14),loc VARCHAR2(13)};GRANT SELECTON DEPTT0 SUE;If Sue needs to select from Scott‘s DEPT table, which command should she use？（）

A.SELECT*FROMDEPT；

B.SELECT*FROMSCOTT.DEPT；

C.SELECT*FROMDBASCOTTDEPT；

D.SELECT*FROMALL_USERSWHEREUSER_NAME=‘；SCOTT‘；ANDTABLENAME=‘；DEPT‘；；

A.SELECT user FROM V$DBA

B.SELECT user FROM dual

C.SELECT name FROM dual

D.SELECT name FROM V$DBA