DBMS Multiple choice Questions and Answers-RDBMS

1.	State true or false: SQL specifies a way of mentioning functional dependencies
a.	True
b.	False
c.	May be
d.	Can't say

Answer: (b).False

2.	State true or false: Most current database systems do not support constraints on materialized view
a.	True
b.	False
c.	May be
d.	Can't say

Answer: (a).True

3.	Multi valued dependencies are also called as __________
a.	Equality generating dependencies
b.	Tuple generating dependencies
c.	Multi-purpose dependencies
d.	None of the mentioned

Answer: (b).Tuple generating dependencies

4.	Functional dependencies are sometimes referred to as ________
a.	Equality generating dependencies
b.	Tuple generating dependencies
c.	Multi-purpose dependencies
d.	None of the mentioned

Answer: (a).Equality generating dependencies

5.	The _______ is a set of all functional and multi values dependencies implied by a set of functional dependencies
a.	Star
b.	Closure
c.	Derivation
d.	Evolution

Answer: (b).Closure

6.	State true or false: If a relational schema is in _______ NF and A is a subset of R and B is also a subset of R then it is that A is a superkey is a trivial multi values dependency.
a.	1
b.	2
c.	3
d.	4

Answer: (d).4

7.	Which of the following normal forms does not exist?
a.	BCNF
b.	PJNF
c.	5NF
d.	None of the mentioned

Answer: (d).None of the mentioned

8.	Choose the correct statement regarding superkeys
a.	A superkey is an attribute or a group of multiple attributes that can uniquely identify a tuple
b.	A superkey is a tuple or a set of multiple tuples that can uniquely identify an attribute
c.	Every superkey is a candidate key
d.	A superkey is an attribute or a set of attributes that distinguish the relation from other relations

Answer: (a).A superkey is an attribute or a group of multiple attributes that can uniquely identify a tuple

9.	What is an Instance of a Database?
a.	The logical design of the database system
b.	The entire set of attributes of the Database put together in a single relation
c.	The state of the database system at any given point of time
d.	The initial values inserted into the Database immediately after its creation

Answer: (c).The state of the database system at any given point of time

10.	What is a foreign key?
a.	A foreign key is a primary key of a relation which is an attribute in another relation
b.	A foreign key is a superkey of a relation which is an attribute in more than one other relations
c.	A foreign key is an attribute of a relation that is a primary key of another relation
d.	A foreign key is the primary key of a relation that does not occur anywhere else in the schema

Answer: (c).A foreign key is an attribute of a relation that is a primary key of another relation