单选题The command echo $! will produce what output？（）Athe process id of last background commandBthe exit status of the last commandCthe exit status of the last background commandDthe process id of the current shellEthe name of the command being executed

题目
单选题
The command echo $! will produce what output？（）
A

 the process id of last background command

B

 the exit status of the last command

C

 the exit status of the last background command

D

 the process id of the current shell

E

 the name of the command being executed

相似考题

1.Examine the structure of the EMPLOYEES table:Column name Data type RemarksEMPLOYEE_ID NUMBER NOT NULL, Primary KeyLAST_NAME VARCNAR2(30)FIRST_NAME VARCNAR2(30)JOB_ID NUMBERSAL NUMBERMGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBERYou need to create an index called NAME_IDX on the first name and last name fields of the EMPLOYEES table. Which SQL statement would you use to perform this task? （）A. CREATE INDEX NAME _IDX (first_name, last_name);B. CREATE INDEX NAME _IDX (first_name, AND last_name)C. CREATE INDEX NAME_IDX ON (First_name, last_name);D. CREATE INDEX NAME_IDX ON employees (First_name, AND last_name);E. CREATE INDEX NAME_IDX ON employees (First_name, last_name);F. CREATE INDEX NAME_IDX FOR employees (First_name, last_name);

2.Examine the data in the EMPLOYEES and DEPARTMENTS tables.EMPLOYEESLAST_NAME DEPARTMENT_ID SALARYGetz 10 3000Davis 20 1500Bill 20 2200Davis 30 5000Kochhar 5000DEPARTMENTSDEPARTMENT_ID DEPARTMENT_NAME10 Sales20 Marketing30 Accounts40 AdministrationYou want to retrieve all employees, whether or not they have matching departments in the departments table.Which query would you use?（）A. SELECT last_name, department_name FROM employees , departments(+);B. SELECT last_name, department_name FROM employees JOIN departments(+);C. SELECT last_name, department_name ON (e. department_ id = d. departments_id); FROM employees(+) e JOIN departments dD. SELECT last_name, department_name FROM employees e RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);E. SELECT last_name, department_name FROM employees(+) , departments ON (e. department _ id = d. department _id);F. SELECT last_name, department_name FROM employees e LEFT OUTER JOIN departments d ON (e. department _ id = d. department _id);

3.Whichofthefollowingisthecorrectformatfor／etc／inittabentries()A.Runlevel：Action：Identifier：CommandB.Identifier：Runlevel：Action：CommandC.Command：Action：Identifier：ProcessD.Process：Runlevel：Command：Identifier

4.ExhibitExamine the data in the EMPLOYEES and DEPARTMENTS tables.You want to retrieve all employees‘ last names, along with their manager‘s last names and their department names. Which query would you use?（）A. SELECT last_name, manager_id, department_name FROM employees e FULL OUTER JOIN department d ON (e.department_id = d.department_id);B. SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.managaer_id = m.employee_id) LEFT OUTER JOIN department d ON (e.department_id = d.department_id);C. SELECT e.last_name, m.last_name, department_name FROM employees e RIGT OUTER JOIN employees m on ( e.manager_id = m.employee_id) FULL OUTER JOIN department d ON (e.department_id = d.department_id);D. SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGT OUTER JOIN department d ON (e.department_id = d.department_id);E. SELECT e.last_name, m.last_name, department_name FROM employees e RIGHT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id)F. SELECT last_name, manager_id, department_name FROM employees e JOIN department d ON (e.department_id = d.department_id);

参考答案和解析
正确答案： A
解析： 暂无解析
更多“单选题The command echo $! will produce what output？（）A  the process id of last background commandB  the exit status of the last commandC  the exit status of the last background commandD  the process id of the current shellE  the name of the command being exe”相关问题

  • 第1题：

    The administrator wants to verify the current state of the OSPF database loading process. Which show command should the administrator use?()

    A. show ip ospf [process - id] interface

    B. show ip ospf neighbor

    C. show ip ospf [process - id]

    D. show ip ospf [process - id area - id] database


    参考答案：B

  • 第2题：

    Which statement is true regarding the Archiver （ARCn） process，archived log files，and recovery？ （）

    • A、A database backup, combined with archived redo log files, guarantees that all committed data can be recovered to the point of failure. 
    • B、During recovery the ARCn background process copies its redo entries identified for recovery by the control file to the data files. 
    • C、After each write to an archived log, the mandatory background process ARCn writes its log sequence number and the first and last SCN number within the log sequence to the control file. 
    • D、At database recover time, and archived redo log is uniquely identified for recovery use by its redo thread number and destination ID number retrieved from the control file.

    正确答案:A

  • 第3题：

    Click the Exhibit button and examine the data in the EMPLOYEES and DEPARTMENTS tables.You want to retrieve all employees, whether or not they have matching departments in the departments table. Which query would you use?（）

    • A、SELECT last_name, department_name FROM employees NATURAL JOIN departments;
    • B、SELECT last_name, department_name FROM employees JOIN departments ;
    • C、SELECT last_name, department_name FROM employees e JOIN departments d ON (e.department_id = d.department_id);
    • D、SELECT last_name, department_name FROM employees e RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);
    • E、SELECT last_name, department_name FROM employees FULL JOIN departments ON (e.department_id = d.department_id);
    • F、SELECT last_name, department_name FROM employees e LEFT OUTER JOIN departments d ON (e.department_id = d.department_id);

    正确答案:F

  • 第4题：

    Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMPLOYEE_ID NUMBER DEPARTMENT_ID NUMBER MANAGER_ID NUMBER LAST_NAME VARCHAR2(25) DEPARTMENTS DEPARTMENT_ID NUMBER MANAGER_ID NUMBER DEPARTMENT_NAME VARCHAR2(35) LOCATION_ID NUMBER You want to create a report displaying employee last names, department names, and locations. Which query should you use?（）

    • A、SELECT e.last_name, d. department_name, d.location_id FROM employees e NATURAL JOIN departments D USING department_id ;
    • B、SELECT last_name, department_name, location_id FROM employees NATURAL JOIN departments WHERE e.department_id =d.department_id;
    • C、SELECT e.last_name, d.department_name, d.location_id FROM employees e NATURAL JOIN departments d;
    • D、SELECT e.last_name, d.department_name, d.location_id FROM employees e JOIN departments d USING (department_id );

    正确答案:D

  • 第5题：

    Examine the structure of the EMPLOYEES table: Column name Data type Remarks EMPLOYEE_ID NUMBER NOT NULL, Primary Key LAST_NAME VARCNAR2(30) FIRST_NAME VARCNAR2(30) JOB_ID NUMBER SAL NUMBER MGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBER You need to create an index called NAME_IDX on the first name and last name fields of the EMPLOYEES table. Which SQL statement would you use to perform this task? （）

    • A、CREATE INDEX NAME _IDX (first_name, last_name);
    • B、CREATE INDEX NAME _IDX (first_name, AND last_name)
    • C、CREATE INDEX NAME_IDX ON (First_name, last_name);
    • D、CREATE INDEX NAME_IDX ON employees (First_name, AND last_name);
    • E、CREATE INDEX NAME_IDX ON employees (First_name, last_name);
    • F、CREATE INDEX NAME_IDX FOR employees (First_name, last_name);

    正确答案:E

  • 第6题：

    Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMPLOYEE_ID NUMBER DEPARTMENT_ID NUMBER MANAGER_ID NUMBER LAST_NAME VARCHAR2(25) DEPARTMENTS DEPARTMENT_ID NUMBER MANAGER_ID NUMBER DEPARTMENT_NAME VARCHAR2(35) LOCATION_ID NUMBER You want to create a report displaying employee last names, department names, and locations. Which query should you use to create an equi-join?（）

    • A、SELECT last_name, department_name, location_id FROM employees , department ;
    • B、SELECT employees.last_name, departments.department_name, departments.location_id FROM employees e, departments D WHERE e.department_id = d.department_id;
    • C、SELECT e.last_name, d.department_name, d.location_id FROM employees e, departments D WHERE manager_id = manager_id;
    • D、SELECT e.last_name, d.department_name, d.location_id FROM employees e, departments D WHERE e.department_id = d.department_id;

    正确答案:D

  • 第7题：

    单选题
    Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMPLOYEE_ID NUMBER DEPARTMENT_ID NUMBER MANAGER_ID NUMBER LAST_NAME VARCHAR2(25) DEPARTMENTS DEPARTMENT_ID NUMBER MANAGER_ID NUMBER DEPARTMENT_NAME VARCHAR2(35) LOCATION_ID NUMBER You want to create a report displaying employee last names, department names, and locations. Which query should you use to create an equi-join?（）
    A

    SELECT last_name, department_name, location_id FROM employees , department ;

    B

    SELECT employees.last_name, departments.department_name, departments.location_id FROM employees e, departments D WHERE e.department_id = d.department_id;

    C

    SELECT e.last_name, d.department_name, d.location_id FROM employees e, departments D WHERE manager_id = manager_id;

    D

    SELECT e.last_name, d.department_name, d.location_id FROM employees e, departments D WHERE e.department_id = d.department_id;


    正确答案： D
    解析： 暂无解析

  • 第8题：

    单选题
    What is the correct command to set the router ID for an OSPFv3 process？（）
    A

    router-id 1.2.3.4

    B

    router-id 2011：：1

    C

    router-id Loopback0

    D

    router-id FF02：：5


    正确答案： D
    解析： 暂无解析

  • 第9题：

    单选题
    Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2 (25) LAST_NAME VARCHAR2 (25) HIRE_DATE DATE Which UPDATE statement is valid?（）
    A

    UPDATE employees SET first_name = 'John' SET last_name = 'Smith' WHERE employee_id = 180;

    B

    UPDATE employees SET first_name = 'John', SET last_name = 'Smoth' WHERE employee_id = 180;

    C

    UPDATE employee SET first_name = 'John' AND last_name = 'Smith' WHERE employee_id = 180;

    D

    UPDATE employee SET first_name = 'John', last_name = 'Smith' WHERE employee_id = 180;


    正确答案： C
    解析： 暂无解析

  • 第10题：

    单选题
    The command echo $! will produce what output？（）
    A

     the process id of last background command

    B

     the exit status of the last command

    C

     the exit status of the last background command

    D

     the process id of the current shell

    E

     the name of the command being executed


    正确答案： D
    解析： 暂无解析

  • 第11题：

    单选题
    The administrator wants to verify the current state of the OSPF database loading process. Which show command should the administrator use?（）
    A

    show ip ospf [process - id] interface

    B

    show ip ospf neighbor

    C

    show ip ospf [process - id]

    D

    show ip ospf [process - id area - id] database


    正确答案： A
    解析： 暂无解析

  • 第12题：

    单选题
    Which statement is true regarding the Archiver （ARCn） process，archived log files，and recovery？ （）
    A

    A database backup, combined with archived redo log files, guarantees that all committed data can be recovered to the point of failure. 

    B

    During recovery the ARCn background process copies its redo entries identified for recovery by the control file to the data files. 

    C

    After each write to an archived log, the mandatory background process ARCn writes its log sequence number and the first and last SCN number within the log sequence to the control file. 

    D

    At database recover time, and archived redo log is uniquely identified for recovery use by its redo thread number and destination ID number retrieved from the control file.


    正确答案： A
    解析： 暂无解析

  • 第13题：

    The administrator wants to verify the current state of the OSPF database loading process. Which show command should the administrator use?（）

    • A、show ip ospf [process - id] interface
    • B、show ip ospf neighbor
    • C、show ip ospf [process - id]
    • D、show ip ospf [process - id area - id] database

    正确答案:B

  • 第14题：

    The command echo $! will produce what output？（）

    • A、 the process id of last background command
    • B、 the exit status of the last command
    • C、 the exit status of the last background command
    • D、 the process id of the current shell
    • E、 the name of the command being executed

    正确答案:A

  • 第15题：

    The EMPLOYEES table contains these columns: EMPLOYEE_ID NUMBER(4) LAST_NAME VARCHAR2 (25) JOB_ID VARCHAR2(10) You want to search for strings that contain 'SA_' in the JOB_ID column. Which SQL statement do you use?（）

    • A、SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA/_%' ESCAPE '/';
    • B、SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA_';
    • C、SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA_' ESCAPE "/";
    • D、SELECT employee_id, last_name, job_id FROM employees WHERE job_id = '%SA_';

    正确答案:A

  • 第16题：

    Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) Which statement produces the number of different departments that have employees with last name Smith?（）

    • A、SELECT COUNT(*) FROM employees WHERE last_name='Smith';
    • B、SELECT COUNT(dept_id) FROM employees WHERE last_name='Smith';
    • C、SELECT DISTINCT(COUNT(dept_id)) FROM employees WHERE last_name='Smith';
    • D、SELECT COUNT(DISTINCT dept_id) FROM employees WHERE last_name='Smith';
    • E、SELECT UNIQUE(dept_id) FROM employees WHERE last_name='Smith';

    正确答案:D

  • 第17题：

    Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE Which UPDATE statement is valid?（）

    • A、UPDATE employees SET first_name = 'John' SET last_name ='Smith' WHERE employee_id = 180;
    • B、UPDATE employees SET first_name = 'John', SET last_name ='Smith' WHERE employee_id = 180;
    • C、UPDATE employees SET first_name = 'John' AND last_name ='Smith' WHERE employee_id = 180;
    • D、UPDATE employees SET first_name = 'John', last_name ='Smith' WHERE employee_id = 180;

    正确答案:D

  • 第18题：

    单选题
    You are maintaining your database in Oracle10g. You are required to view the list of files that have not been backed up for the last seven days. Which RMAN command will you use？（）
    A

     LIST command

    B

     CROSSCHECK command

    C

     REPORT command

    D

     SHOW command


    正确答案： C
    解析： 暂无解析

  • 第19题：

    单选题
    The EMPLOYEES table contains these columns: EMPLOYEE_ID NUMBER(4) LAST_NAME VARCHAR2 (25) JOB_ID VARCHAR2(10) You want to search for strings that contain 'SA_' in the JOB_ID column. Which SQL statement do you use?（）
    A

    SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA/_%' ESCAPE '/';

    B

    SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA_';

    C

    SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA_' ESCAPE /;

    D

    SELECT employee_id, last_name, job_id FROM employees WHERE job_id = '%SA_';


    正确答案： A
    解析： 暂无解析

  • 第20题：

    单选题
    Examine the data in the EMPLOYEES and DEPARTMENTS tables. EMPLOYEES LAST_NAME DEPARTMENT_ID SALARY Getz 10 3000 Davis 20 1500 Bill 20 2200 Davis 30 5000 Kochhar 5000 DEPARTMENTS DEPARTMENT_ID DEPARTMENT_NAME 10 Sales 20 Marketing 30 Accounts 40 Administration You want to retrieve all employees, whether or not they have matching departments in the departments table. Which query would you use?（）
    A

    SELECT last_name, department_name FROM employees , departments(+);

    B

    SELECT last_name, department_name FROM employees JOIN departments(+);

    C

    SELECT last_name, department_name ON (e. department_ id = d. departments_id); FROM employees(+) e JOIN departments d

    D

    SELECT last_name, department_name FROM employees e RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);

    E

    SELECT last_name, department_name FROM employees(+) , departments ON (e. department _ id = d. department _id);

    F

    SELECT last_name, department_name FROM employees e LEFT OUTER JOIN departments d ON (e. department _ id = d. department _id);


    正确答案： C
    解析： 暂无解析

  • 第21题：

    单选题
    Click the Exhibit button and examine the data in the EMPLOYEES and DEPARTMENTS tables.You want to retrieve all employees, whether or not they have matching departments in the departments table. Which query would you use?（）
    A

    SELECT last_name, department_name FROM employees NATURAL JOIN departments;

    B

    SELECT last_name, department_name FROM employees JOIN departments ;

    C

    SELECT last_name, department_name FROM employees e JOIN departments d ON (e.department_id = d.department_id);

    D

    SELECT last_name, department_name FROM employees e RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);

    E

    SELECT last_name, department_name FROM employees FULL JOIN departments ON (e.department_id = d.department_id);

    F

    SELECT last_name, department_name FROM employees e LEFT OUTER JOIN departments d ON (e.department_id = d.department_id);


    正确答案： B
    解析： 暂无解析

  • 第22题：

    单选题
    Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMPLOYEE_ID NUMBER DEPARTMENT_ID NUMBER MANAGER_ID NUMBER LAST_NAME VARCHAR2(25) DEPARTMENTS DEPARTMENT_ID NUMBER MANAGER_ID NUMBER DEPARTMENT_NAME VARCHAR2(35) LOCATION_ID NUMBER You want to create a report displaying employee last names, department names, and locations. Which query should you use?（）
    A

    SELECT e.last_name, d. department_name, d.location_id FROM employees e NATURAL JOIN departments D USING department_id ;

    B

    SELECT last_name, department_name, location_id FROM employees NATURAL JOIN departments WHERE e.department_id =d.department_id;

    C

    SELECT e.last_name, d.department_name, d.location_id FROM employees e NATURAL JOIN departments d;

    D

    SELECT e.last_name, d.department_name, d.location_id FROM employees e JOIN departments d USING (department_id );


    正确答案： D
    解析： 暂无解析

  • 第23题：

    单选题
    Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) Which statement produces the number of different departments that have employees with last name Smith?（）
    A

    SELECT COUNT (*) FROM employees WHERE last _name='smith';

    B

    SELECT COUNT (dept_id) FROM employees WHERE last _name='smith';

    C

    SELECT DISTINCT (COUNT (dept_id) FROM employees WHERE last _name='smith';

    D

    SELECT COUNT (DISTINCT dept_id) FROM employees WHERE last _name='smith';

    E

    SELECT UNIQE (dept_id) FROM employees WHERE last _name='smith';


    正确答案： C
    解析： 暂无解析

  • 第24题：

    单选题
    Examine the structure of the EMPLOYEES table: Column name Data type Remarks EMPLOYEE_ID NUMBER NOT NULL, Primary Key LAST_NAME VARCNAR2(30) FIRST_NAME VARCNAR2(30) JOB_ID NUMBER SAL NUMBER MGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBER You need to create an index called NAME_IDX on the first name and last name fields of the EMPLOYEES table. Which SQL statement would you use to perform this task? （）
    A

    CREATE INDEX NAME _IDX (first_name, last_name);

    B

    CREATE INDEX NAME _IDX (first_name, AND last_name)

    C

    CREATE INDEX NAME_IDX ON (First_name, last_name);

    D

    CREATE INDEX NAME_IDX ON employees (First_name, AND last_name);

    E

    CREATE INDEX NAME_IDX ON employees (First_name, last_name);

    F

    CREATE INDEX NAME_IDX FOR employees (First_name, last_name);


    正确答案： F
    解析： 暂无解析

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