Relational Model, Language and Systems Questions and Answers

Multiple Choice Questions and Answers

Question 1 : A table with columns and rows is called as a 

(a) Table
(b) Relation
(c) Key
(d) None of the above

Answer : (b)

Question 2 : Entities are nothing else but

(a) Relations
(b) DBMS
(c) Attributes
(d) None of the above

Answer : (a)

Question 3 : Attributes correspond to

(a) Rows of a table
(b) Columns of a table
(c) Degree of a table
(d) None of the above

Answer : (b)

Question 4 : A row of a relation is called as a 

(a) Domain
(b) Tuple
(c) Relation
(d) None of the above

Answer : (b)

Question 5 : A set of tuples at any given instant of time is called as 

(a) Table
(b) Relation
(c) Extension
(d) None of the above

Answer : (c)

Question 6 : The number of tuples of a relation is its

(a) Degree
(b) Intension
(c) Cardinality
(d) None of the above

Answer : (c)

Question 7 : A relation with degree, N, is known as 

(a) N-ary relation
(b) 1-ary relation
(c) 2-ary relation
(d) None of the above

Answer : (a)

Question 8 : Which of the following is a correct form of the equation

(a) CK = SK + PK
(b) CK = SK – PK
(c) CK = SK * PK
(d) None of the above

Answer : (b)

Question 9 : Those candidate keys which are not currently selected as the primary key are called as 

(a) Super keys
(b) Candidate key
(c)  Alternate key
(d) None of the above

Answer : (c)

Question 10 : Which of the following is correct is AK = Alternate Key, CK = Candidate Key and PK = Primary Key

(a) AK = CK – PK
(b) AK = CK + PK
(c) AK = SK – PK
(d) None of the above

Answer : (a)

Question 11 : A key that has no meaning to the business or organization is

(a) Candidate key
(b) Alternate key
(c) Artificial key
(d) None of the above

Answer : (c)

Question 12 : The column in the child table that references a primary key of the parent table is called as 

(a) Candidate key
(b) Foreign key
(c) Composite key
(d) None of the above

Answer : (b)

Question 13 : A rule that states that in a base relation, the value of attribute of a primary key cannot be null is called as

(a) Entity integrity rule
(b) Referential integrity rule
(c) Security integrity rule
(d) None of the above

Answer : (a)

Question 14 : A NULL means

(a) Unknown
(b) Known
(c) known partially
(d) None of the above

Answer : (a)

Question 15 : Dr. E.F.Codd gave

(a) 10-rules
(b) 11-rules
(c) 12-rules
(d) 13-rules

Answer : (c)

Question 16 : A virtual relation is also known as a

(a) View
(b) Table
(c) Snapshot
(d) None of the above

Answer : (a)

Question 17 : In order to perform Union operation on two relations, both operand and relations must be 

(a) Union-compatible
(b) Set-compatible
(c) Difference-compatible
(d) None of the above

Answer : (a)

Question 18 : Which is true out of the following

(a) (A-B) = (B-A)
(b) (A-B) ≠ (B-A)
(c) (B-A) = (B-C)
(d) None of the above

Answer : (b)

Question 19 : Select-operator (σ) words row wise whereas project-operator (π) works

(a) Row-wise only
(b) Column wise
(c) Both ‘a’ and ‘b’
(d) None of the above

Answer : (b)

Question 20 : When we want to display records with attributes from many relations then we use 

(a) SELECT operation
(b) PROJECT operation
(c) JOIN operation
(d) None of the above

Answer : (c)

Question 21 : Relational calculus describes about 

(a) ‘How’ to evaluate a query
(b) ‘What’ is to be retrieved
(c) ‘When’ to evaluate a query
(d) None of the above

Answer : (b)

Question 22 : QUEL is a TRC language of which RDBMS – 

(a) INGRESS
(b) DB2
(c) Oracle 8i
(d) None of the above

Answer : (a)

Question 23 : How many tables can be joined to create a view

(a) 1
(b) 2
(c) Depends on DBMS
(d) None of the above

Answer : (d)

Question 24 : What is cardinality of a table with 50 rows and 5 columns?

(a) 50
(b) 5
(c) 250
(d) None of the above

Answer : (a)

Question 25 : What is the degree of a table with 50 rows and 5 columns?

(a) 50
(b) 5
(c) 250
(d) None of the above

Answer : (b)

DBMS Questions and Answers