数据库试题答案 英文卷

哈尔滨理工大学 2007－2008学年 第一学期考试试题答案 A 卷 考试科目： 数据库系统 考试时间：120分钟 试卷总分100分 考试班级：软件06-1、2、3、4、5、6班 题号 I II III IV V 总分 得分 评卷教师 I 、Choice Questions 1、 A 2、 A 3、 D 4、 D 5、 D 6、 B 7、 B 8、 C 9、 C 10、 C II 、Blank-filling Questions 1. ① conditions , ② actions 2. A= 225 ; B= 225 3. ① parser and translator , ② execution plan 4. records 5. 8 6. speed up
7. data
II 、 Briefly description questions. (There are 4 questions, totally 16 marks, and
each question worth 4 marks.）
1. FOUR of the following five DBA duties:
● Schema definition
● Storage structure and access method definition
● Schema and physical organization modification
● Granting user authority to access the database
● Routine maintenance
2. A transaction is a unit of program execution that accesses and possibly updates
various data items.
ACID properties of transaction are: atomicity, consistency, isolation, and durability. 装
订
线
班级： 学号：
姓名：
3.AG →I is a member of F+.
By augmenting A →C with G, to get AG →CG and then transitivity with CG →I, we can get AG →I.
CG →HI is a member of F+.
By augmenting CG →I to infer CG → CG I, and augmenting of CG →H to infer CGI →HI, and then transitivity, we can get CG →HI.
4.The processes of computing result of (AG)+ have been shown below.
① result = AG
② result = ABCG (A →C and A → B)
③ result = ABCGH (CG →H and CG ⊆AGBC)
④ result = ABCGHI (CG →I and CG ⊆AGBCH)
III、C omplete the following queries.
1.
①∏customer_name (borrower) ⋃∏customer_name (depositor)
② account ←account ⋃{(“Perryridge”, A-911, 4500)}
depositor ←depositor ⋃{(“Smith”, A-911)}
2.
①CREATE TABLE SC
( Sno int,
Cno int,
Grade int,
PRIMARY KEY (Sno, Cno),
FOREIGN KEY (Sno) REFERENCES S,
FOREIGN KEY (Cno) REFERENCES C,
CHECK (Grade >= 0))
②SELECT Sno, SNAME
FROM S
WHERE AGE>22 AND SEX=‘M’;
③SELECT Sno
FROM SC AS X, SC AS Y
WHERE X.Sno=Y.Sno AND o !=o
④SELECT SNAME, AGE
FROM S
WHERE SEX=‘M’ AND AGE> ALL (SELECT AGE
FROM S
WHERE SEX=‘F’)
哈尔滨理工大学
2007－2008学年第一学期考试试题答案A卷 SELECT CNAME, AVG(GRADE)
FROM C, SC
WHERE C.C#=SC.C# AND TEACHER=‘LIU’
GROUP BY C.C#
IV、Resolve the following questions of designing.
1、E-R diagram for the university registrar’s office：
2、The relational database corresponding to the preceding E-R diagram：
student( sid, name, program)
course_offering(courseno, secno, year, semester, time, room)
instructor(iid, name, department, title)
courses(courseno, title, credits, syllabus)
enrolls(sid, courseno, grade)
teaches( iid, courseno)
requires(couseno, prerequisite, maincourse)。