Database Management Systems Questions

Database Management Systems (COME3106)

Computer Engineering - COM

Semester: First Semester

Level: 300

Year: 2019

Answers (200 )

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School: NAHPI

Department:

Computer Science

Course title: Database Management Systems

Code:

COME3106

Semester: 1

Credit value: 4

Academic Year: 2018/2019

Time allowed: 1H3Omins

First Semester Exams

Instructions: Choose the letter corresponding to the best answer. Answer

ALL questions

relational database consists of a collection of:

a) tables b) fields c) records d) keys

A ____

in a table represents a relationship among a set of values.

a) column b) key c) row d) entry

The term ________ is used to refer to a roz.

a) attribute b) tuple c) field d) instance

The term attribute refers to a ______

a) record b) column c) tuple d) key

For each of attribute of a relation, there is a set of permitted values, called the ___

of that attribute.

a) domain b) relation c) set d) schema

Database _________ which is the logical design of the database, and the database

_________ which is a snapshot of the data in the database at a given instant in time.

a) instance, schema b) relation, schema c) relation, domain d) schema, instance

Course (course id, sec id, semester).

Here the

course id, sec id

and

semester

are

and course is a ______

a) relations, attribute b) attributes, relation c) tuple, relation d) tuple,

attributes

Department (dept_name, building, budjet)

and

Employee (employee_id, name, dept

name, salary).

Here the

dept_name

attribute appears in both relations. Here using

common attributes in relation schema

one way of relating ________ relations.

a) attributes of common b) tuple of common c) tuple of distinct d) attributes of distinct

A domain is atomic if elements of the domain are considered to be ________ units.

a) any b) indivisible c) constant d) divisible

10. The tuples of the relations can be of _______ order.

a) any b)same c) sorted d) constant

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11. Which one of the following is a set of one or more attributes taken collectively to

uniquely identify a record?

a) candidate key b) sub key c) super key d) foreign key

12. Consider attributes ID, CITY, and NAME. which one of this can be considered as a super

key?

a) NAME b) ID c) CITY d) CITY

13.

subset of a super key is a candidate key under what condition?

a) no proper subset is a super key b) all subsets are super keys c) subset is a

super key d) each subset is a super key

14. A ________ is a property of the entire relation, rather than of the individual tuples in

which each tuple is unique.

a) rows b) key a) attribute d) fields

15. Which one of the following attribute can be taken as a primary key?

a) Name b) Street c) Id d) Department

16. Which one of the following attribute cannot be taken as a primary key?

a) Id b) Register number c) Dept_Id d) bate of birth

17. An attribute of a relation is a foreign key if the ________ key from one relation is

used as an attribute in that relation.

a) candidate b) primary c) super d) sub

18. The relation with the attribute which is the primary key

referenced in another relation.

The relation which has the attribute as a primary key is called:

a) referential relation b) referencing relation c) referenced relation d)

referred relation

19. The _______ is the one in which the primary key of one relation is used as a normal

attribute in another relation.

a) referential relation b) referencing relation c) referenced relation d) referred

relation

20.A _____________ integrity constraint requires that the values appearing in specified

attributes of any tuple in the referencing relation also appear in specified attributes of

at least one tuple in the referenced relation.

a) referential b) referencing c) specific d) primary

21. Using which language can a user request information from a database?

a) Query b) Relational c) Structural d) Compiler

22. Student(Ib, name, dept name, tot_cred).

In this query which attributes form the

primary key?

a) Name b) dept_name c) tot_cred d) ID

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23.The _________ operation allows the combining of two relations by merging pairs of tuples,

one from each relation, into a single tuple.

a) select b) join c) union d) intersection

24.The ______________ operator takes the results of two queries and returns only rows that

appear in both result sets.

a) Union b) intersect c) difference d) projection

25.The most commonly used operation in relational algebra for projecting a set of tuple from

a relation is:

a) Join b) Projection c) Select d) Union

26.Which of the following is used to define the structure of the relation, deleting relations

and relating schemas?

a) DML (Data Manipulation Language) b) DDL(Data Definition Language) c) Query

d) Relational Schema

27.CREATE TABLE employee(name VARCHAR,..)

What type of statement is this?

a) DML b) DDL c) View d) Integrity constraint

28.SELECT * FROM employee

What type of statement

this?

a) DML b) DDL c) View d) Integrity constraint

29.To remove a relation from an SQL database, we use the ___________ command.

a) Delete b) Purge c) Remove d) Drop table

30. INSERT INTO instructor VALUES (1,...)

What type of statement is this?

a) Query b) DML c) Relational d) DDL

31. Which of the following symbols represent entity sets in an ER diagram?

a) divided rectangles b) diamonds c) lines d) undivided rectangles

32. Which of the following symbols represent relationship sets in an ER diagram?

a) divided rectangles b) diamonds c) lines d) undivided rectangles

33. What does a directed line (n) from a relationship set to two entity sets mean?

a) one-one b) many-one c) many-many d) one-many

34. A function that has no partial dependencies

in _________ form:

a) 3NF b) 2NF c) 4NF d) BCNF

35. If every non-key attribute is functionally dependent on the primary key, then the relation

will be in:

a) 1NF b) 2NF c) 3NF d) 4NF

36. A table is in 2NF if it is in 1NF and if:

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a) no column that is not part of the primary key is dependent on only a portion of the

alternate key.

b) no column that is not part of the primary key is dependent on only a portion of the

primary key

c) no column that is not a part of the primary key is dependent on only a portion of the

foreign key

d) none of these '

37. E-R modeling technique is a:

a) top-down approach b) bottom-up approach c) left-right approach d) none of

these

38. The number of entities to which another entity can be associated via a relationship set is

expressed as:

a) entity b) cardinality c)schema d) attributes

39. The data model which describes how the data is actually stored is:

a) internal model b) external model c) logical model d) none of these

40. Data about data

normally termed as:

a) directory b) data bank c) meta data d) data dictionary

41. A data model is:

a) used to describe structure of a database b) set of basic operations on thy-: database

c) both a) and b) d) none of the mentioned

42. DBA stands for:

a) Data Bank

Access

b) Database Access c) Data Bank Administration d)

Database Administrator

43. Which of the following are properties of entities?

a) groups b) table c) attributes d) switchboards

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