Which statement adds a constraint that ensures the CUSTOMER_NAME column of the CUSTOMERS table holds a value?（）

A . ALTER TABLE students ADD PRIMARY KEY student_id; B . ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student _ id); C . ALTER TABLE students ADD CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id); D . ALTER TABLE students MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id)

A . REVOKE DROP ON t1 FROM PUBLIC B . REVOKE UPDATE ON t1 FROM PUBLIC C . REVOKE DELETE ON t1 FROM PUBLIC D . REVOKE CONTROL ON t1 FROM PUBLIC

A . SELECT ADD_MONTHS(MAX(hire_Date), 6) FROM EMP; B . SELECT ROUND(hire_date) FROM EMP; C . SELECT sysdate-hire_date FROM EMP; D . SELECT TO_NUMBER(hire_date + 7) FROM EMP

A . When a file is created in DGROUP1 with the template， it would have three­way mirroring.  B . When a file is created in DGROUP1， the MY_TEMP template becomes the default template. C . When a file is created in DGROUP1 with the template， it would have two­way mirroring and file striping. D . When a file is created in DGROUP1 with the template， it would have three­way mirroring and file striping. E . When a file is created in DGROUP1 with the template， it would have two­way mirroring but no file striping.

A . CREATIVE USER susan; B . CREATIVE OR REPLACE USER susan; C . CREATE NEW USER susan DEFAULT D . CREATE USER susan IDENTIFIED BY blue; E . CREATE NEW USER susan IDENTIFIED BY blue; F . CREATE OR REPLACE USER susan IDENTIFIED BY blue

A .  for （int i=0； i< a.size（）； i++）  System.out.println（a.get（i）））； B .  for （int i=0； i< a.size（）； i++）  System.out.println（a[i]）； C .  while（ iter.hasNext（） ）  System.out.println（iter.next（）） ； D .  for （int i=0， i< a.size（）； i++）  System.out.println（iter[i]）； E .  for （int i=0； i< a.size（）； i++）  System.out.println（iter.get（i））；

A . DELETE employees; B . DESCRIBE employees; C . ROLLBACK TO SAVEPOINT C; D . GRANT SELECT ON employees TO SCOTT; E . ALTER TABLE employees SET UNUSED COLUMN sal; F . Select MAX(sal) FROM employees WHERE department_id = 20

A . The router will prefer the next hop of 172.16.1.1 for packets destined for the 192.168.1.0 network. B . The router will prefer the next hop of 172.26.1.1 for packets destined for the 192.168.1.0 network. C . The router will adve rtise the 192.168.1.0 network only to 172.30.1.1. D . The router will advertise the 192.168.1.0 network only to 172.26.1.1. E . The router will prefer the next hop of 172.26.1.1 for packets except those destined for the 192.168.1.0 network.

A . DELETE employees; B . DESCRIBE employees; C . ROLLBACK TO SAVEPOINT C; D . GRANT SELECT ON employees TO SCOTT; E . ALTER TABLE employees SET UNUSED COLUMN sal; F . SELECT MAX(sal) FROM employees WHERE department_id = 20

A . -xx:+PrintGCDetails B . -xx:+PrintGCTimeStamps   C . -xx:+HandlePromotionFailure D . -verbose:gc E . -server

A . A role can be given to a maximum of 1000 users. B . A user can have access to a maximum of 10 roles. C . A role can have a maximum of 100 privileges contained in it. D . Privileges are given to a role by using the CREATE ROLE statement. E . A role is a named group of related privileges that can be granted to the user. F . A user can have access to several roles, and several users can be assigned the same role.

A .  CREATE TABLESPACE DATA1 DATAFILE ’+grp1/abc（datafile）’； B .  CREATE TABLESPACE DATA1 DATAFILE ’+grp1’； C .  CREATE TABLESPACE DATA1 DATAFILE ’+data1（tempfile）’； D .  CREATE TABLESPACE DATA1 DATAFILE ’+grp1.256.34359’；

A . ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students (student_id); B . ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id); C . ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id); D . ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id); E . ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id)

A . Create the VLAN. B . Name the VLAN. C . Configure an IP address for the VLAN. D . Add the desired ports to the new VLAN. E . Add the VLAN to the VTP domain.

A . /etc/prtconf B . /etc/qconfig C . /etc/lpconfig D . /etc/prtconfig

A . CREATE TABLE EMP9$# AS (empid number(2)); B . CREATE TABLE EMP*123 AS (empid number(2)); C . CREATE TABLE PACKAGE AS (packid number(2)); D . CREATE TABLE 1EMP_TEST AS (empid number(2))

A .  When a file is created in DGROUP1 with the template， it would have three-way mirroring. B .  When a file is created in DGROUP1， the MY_TEMP template becomes the default template. C .  When a file is created in DGROUP1 with the template， it would have two-way mirroring and file striping. D .  When a file is created in DGROUP1 with the template， it would have three-way mirroring and file striping. E .  When a file is created in DGROUP1 with the template， it would have two-way mirroring but no file striping.

A . When a file is created in DGROUP1 with the template， it would have three-way mirroring. B . When a file is created in DGROUP1， the MY_TEMP template becomes the default template. C . When a file is created in DGROUP1 with the template， it would have two-way mirroring and file striping. D . When a file is created in DGROUP1 with the template， it would have three-way mirroring and file striping. E . When a file is created in DGROUP1 with the template， it would have two-way mirroring but no file Striping.

A . ALTER TABLE students ADD PRIMARY KEY _ id; B . ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id); C . ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id; D . ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id); E . ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id)

A.the preliminaries B.the text of the paper C.the reference materials D.all of the above

A.Copy the device driver to the device driver directory. B.Extend the Linux kernel by incorporating the device code. C.Insert the device into the Linux system and allow the system to choose the device files from its device directory. D.Insert the cd-rom with the device driver into the machine Linux will detect it and prompt you through installation.