吉大11春学期《数据库应用技术》在线作业二答案
在线作业, 数据库, 单选题, 答案
一、单选题（共 25 道试题，共 100 分。）V 1.  在SELECT语句的下列子句中，通常和HAVING子句同时使用的是以下哪项？
A. ORDER BY子句
B. WHERE子句
C. GROUP BY子句
D. 均不需要
      满分：4  分
2.  Which of the following is TRUE for all cursors defined as FOR FETCH ONLY?
A. The cursors are unambiguous.
B. Only the first row is returned.
C. Cursor stays open after a commit.
D. A temporary table is created on the server.
      满分：4  分
3.  对于支持小规模的部门级应用，这些应用不需要存取驻留在OS/400、OS/390等平台上的远程数据库，则需要哪种级别的DB2 产品？
A. 企业版
B. 工作组版
C. 企业扩展版
D. 个人版
E. 卫星版
F. 微型版
      满分：4  分
4.  The following commands are issued against a data source containing table user2.org: CREATE ALIAS user1.org FOR sample.org CREATE TABLE org.sample ( c CHAR(1)) CREATE ALIAS sample.org FOR user2.org CREATE ALIAS user2.sample FOR sample.org Given the user SAMPLE issues the following statement: SELECT * FROM sample For which of the following database objects will access be attempted?
A. user2.org
B. org.sample
C. sample.org
D. sample.sample
      满分：4  分
5.  A cursor is declared with the WITH HOLD option. Which of the following statements is always true?
A. The cursor will remain open after a COMMIT.
B. All rows retrieved are locked until a COMMIT.
C. A COMMIT will not be allowed until the cursor is closed.
D. Locks obtained by the cursor will be kept after a COMMIT.
      满分：4  分
6.  使用SQL语句进行查询操作时，若希望查询结果不出现重复元组，应在SELECT子句中使用什么保留字？
A. NIQUE
B. ALL
C. EXCEPT
D. DISTINCT
      满分：4  分
7.  如果用户在SQL语句中没有指定数据库对象的SCHEMA，则其缺省的SCHEMA是：
A. SYSIBM
B. SYSCAT
C. SYSSTAT
D. 该用户连接到数据库时所使用的用户名
E. 以上都不对
      满分：4  分
8.  数据库系统的并发控制的主要方法是采用（）制。
A. 拒绝
B. 改为串行
C. 锁
D. 不加任何控制
      满分：4  分
9.  Given the expression: WITH most_cities AS ( SELECT b.id,b.name,a.cities FROM country a, staff b WHERE a.person = b.id AND cities > :threshold ) SELECT * FROM most_cities In which of the following does MOST_CITIES exist?
A. user tables
B. server memory
C. user table space
D. system catalog tables
      满分：4  分
10.  关系模式中各级模式之间的关系为（）
A. 3NF 2NF 1NF
B. 3NF 1NF 2NF
C. 1NF 2NF 3NF
D. 2NF 1NF 3NF
      满分：4  分
11.  创建一个DMS类型的表空间，可以使用以下哪两种文件系统对象作为容器？
A. 目录
B. 文件
C. DEVICE
      满分：4  分
12.  执行下面两条SQL语句后： CREATE TABLE t1 ( c1 char(10) NOT NULL PRIMARY KEY, c2 int, c3 char(10), c4 char(10) NOT NULL, CONSTRAINT c4 UNIQUE (c1,c4) ) //自动创建索引 CREATE INDEX Index1 ON t1 (c2 ASC) 表t1上有几个索引？
A. 0
B. 1
C. 2
D. 3
E. 4
      满分：4  分
13.  缺省的数据库日志文件的类型是：
A. Circular Log
B. Archival Log
C. Primary Log
D. Secondary log
      满分：4  分
14.  An application uses embedded dynamic SQL to connect to a remote DB2 server and inserts data into the CUST.ORDERS table on that remote DB2 server. To enable access of the remote DB2 server, Administrator FOO needs to create a package with default options such that BAR is the only non-administrative user that can use this package on the remote DB2 server. Which statement describes the privileges that must be granted and/or revoked by FOO to accomplish this?
A. BAR requires EXECUTE privilege on the package and UPDATE privilege on CUST.ORDERS, and the EXECUTE privilege for the package must be revoked from PUBLIC.
B. BAR requires EXECUTE privilege on the package and INSERT privilege on CUST.ORDERS, and the EXECUTE privilege for the package must be revoked from PUBLIC.
C. BAR requires EXECUTE privilege on the package and INSERT privilege on CUST.ORDERS, and the REFERENCES privilege for the package must be revoked from PUBLIC.
D. BAR requires EXECUTE privilege on the package and UPDATE privilege on CUST.ORDERS, and the REFERENCES privilege for the package must be revoked from PUBLIC.
      满分：4  分
15.  给定三个表：学生表S，课程表C和学生选课表SC，它们的结构分别如下： S（S#，SN，SEX，AGE，DEPT） C（C#，CN） SC（S#，C#，GRADE）其中：S#为学号，SN为姓名，SEX为性别，AGE为年龄，DEPT为系别，C#为课程号，CN为课程名，GRADE为成绩。检索选修课程“C2”的学生中成绩最高的学生的学号，正确的SELECT语句是哪个？
A. SELECT S# FROM SC WHERE C#=“C2” AND GRADE >= (SELECT GRADE FROM SC WHERE C#=” C2”)
B. SELECT S# FROM SC WHERE C#=”C2” AND GRADE IN (SELECT GRADE FROM SC WHERE C#=”C2”)
C. SELECT S# FROM SC WHERE C#=”C2” AND GRADE NOT IN (SELECT GRADE FROM SC WHERE C#=”C2”)
D. SELECT S# FROM SC WHERE C#=”C2” AND GRADE>=ALL (SELECT GRADE FROM SC WHERE C#=”C2”)
      满分：4  分
16.  数据库系统的独立性是指（）：
A. 不会因为数据的变化而影响应用程序
B. 不会因为系统数据存储结构与数据逻辑结构的变化而影响应用程序
C. 不会因为存储策略的变化而影响存储结构
D. 不会因为某些存储结构的变化而影响其它的存储结构
      满分：4  分