Database Systems MCQ

Q.1 The physical location of a record is determined by a mathematical formula that transforms a file key into a record location is :

(A) B-Tree File

(B) Hashed File

(C) Indexed File

(D) Sequential file

Ans: B

 

Q.2 Using Relational Algebra the query that finds customers, who have a balance of over 1000 is

(A) πCustomer_name(s balance >1000(Deposit))

(B) σCustomer_name(Pbalance >1000(Deposit))

(C) πCustomer_name(s balance >1000(Borrow))

(D) σCustomer_name(Pbalance >1000(Borrow))

Ans: A

 

Q.3 A primary key is combined with a foreign key creates

(A) Parent-Child relation ship between the tables that connect them.

(B) Many to many relationship between the tables that connect them.

(C) Network model between the tables that connect them.

(D) None of the above.

Ans: A

 

Q.4 In E-R Diagram derived attribute are represented by

(A) Ellipse

(B) Dashed ellipse

(C) Rectangle

(D) Triangle

Ans B

 

Q.5 Cross Product is a:

(A) Unary Operator

(B) Ternary Operator

(C) Binary Operator

(D) Not an operator

Ans: C

 

Q.6 An instance of relational schema R (A, B, C) has distinct values of A including NULL values. Which one of the following is true?

(A) A is a candidate key

(B) A is not a candidate key

(C) A is a primary Key

(D) Both (A) and (C)

Ans: B

 

Q.7 Consider the join of a relation R with relation S. If R has m tuples and S has n tuples, then the maximum size of join is:

(A) mn

(B) m+n

(C) (m+n)/2

(D) 2(m+n)

Ans: A

 

Q.8 The natural join is equal to :

(A) Cartesian Product

(B) Combination of Union and Cartesian product

(C) Combination of selection and Cartesian product

(D) Combination of projection and Cartesian product

Ans: D

 

Q.9 Which one of the following is not true for a view:

(A) View is derived from other tables.

(B) View is a virtual table.

(C) A view definition is permanently stored as part of the database.

(D) View never contains derived columns.

Ans: C

 

Q.10 A primary key if combined with a foreign key creates

(A) Parent-Child relationship between the tables that connect them.

(B) Many to many relationship between the tables that connect them.

(C) Network model between the tables that connect them.

(D) None of the above.

Ans: A

 

Q.11 In E-R Diagram relationship type is represented by

(A) Ellipse

(B) Dashed ellipse

(C) Rectangle

(D) Diamond

Ans: D

 

Q.12 Hierarchical model is also called

(A) Tree structure

(B) Plex Structure

(C) Normalize Structure

(D) Table Structure

Ans: A

 

Q.13 To delete a particular column in a relation the command used is:

(A) UPDATE

(B) DROP

(C) ALTER

(D) DELETE

Ans: C

 

Q.14 The ______ operator is used to compare a value to a list of literals values that have been specified.

(A) BETWEEN

(B) ANY

(C) IN

(D) ALL

Ans: A

 

Q.15 A logical schema

A) is the entire database

B) is a standard way of organizing information into a accessible part

C) describe how data is actually stored on disk

D) none of these

Ans: D

 

Q.16 A B-tree of order m has maximum of _____________ children

(A) m

(B) m+1

(C) m-1

(D) m/2

Ans: A

 

Q.17 _____________ function divides one numeric expression by another and returns the remainder.

(A) POWER

(B) MOD

(C) ROUND

(D) REMAINDER

Ans: B

 

Q.18 A data manipulation command the combines the records from one or more tables is called

(A) SELECT

(B) PROJECT

(C) JOIN

(D) PRODUCT

Ans: C

 

Q.19 In E-R diagram generalization is represented by

(A) Ellipse

(B) Dashed ellipse

(C) Rectangle

(D) Triangle

Ans: D

 

Q.20 _________ is a virtual table that draws its data from the result of an SQL SELECT statement.

(A) View

(B) Synonym

(C) Sequence

(D) Transaction

Ans: A

 

Q.21 The method of access which uses key transformation is known as

(A) Direct

(B) Hash

(C) Random

(D) Sequential

Ans: B

 

Q.22 A table joined with itself is called

(A) Join

(B) Self Join

(C) Outer Join

(D) Equi Join

Ans: B

 

Q.23 _________ data type can store unstructured data

(A) RAW

(B) CHAR

(C) NUMERIC

(D) VARCHAR

Ans: A

 

Q.24 Which two files are used during operation of the DBMS

(A) Query languages and utilities

(B) DML and query language

(C) Data dictionary and transaction log

(D) Data dictionary and query language

Ans: C