100 TOP DATABASE MANAGEMENT SYSTEM Questions and Answers

DATABASE MANAGEMENT SYSTEM Questions and Answers :- 

1. A Database Management System (DBMS) is
A. Collection of interrelated data
B. Collection of programs to access data
C. Collection of data describing one particular enterprise
D. All of the above

2. Which of the following is not a level of data abstraction?
A. Physical Level
B. Critical Level
C. Logical Level
D. View Level

3. Disadvantages of File systems to store data is:
A. Data redundancy and inconsistency
B. Difficulty in accessing data
C. Data isolation
D. All of the above

4. In an Entity-Relationship Diagram Rectangles represents
A. Entity sets
B. Attributes
C. Database
D. Tables

5. Which of the following is not a Storage Manager Component?
A. Transaction Manager
B. Logical Manager
C. Buffer Manager
D. File Manager

6. Data Manipulation Language enables users to
A. Retrieval of information stored in database
B. Insertion of new information into the database
C. Deletion of information from the database
D. All of the above

7. Which of the following is not an Schema?
A. Database Schema
B. Physical Schema
C. Critical Schema
D. Logical Schema

8. Which of the following is Database Language?
A. Data Definition Language
B. Data Manipulation Language
C. Query Language
D. All of the above

9. Which of the following in not a function of DBA?
A. Network Maintenance
B. Routine Maintenance
C. Schema Definition
D. Authorization for data access

10. Which of the following is a Data Model?
A. Entity-Relationship model
B. Relational data model
C. Object-Based data model
D. All of the above

1. Which of the following represents a relationship among a set of values.
A. A Row
B. A Table
C. A Field
D. A Column

2. Column header is refer as
A. Table
B. Relation
C. Attributes
D. Domain

3. A Relation is a
A. Subset of a Cartesian product of a list of attributes
B. Subset of a Cartesian product of a list of domains
C. Subset of a Cartesian product of a list of tuple
D. Subset of a Cartesian product of a list of relations

4. In mathematical term Table is referred as
A. Relation
B. Attribute
C. Tuple
D. Domain

5. In mathematical term Row is referred as
A. Relation
B. Attribute
C. Tuple
D. Domain

6. _______ allow us to identify uniquely a tuple in the relation.
A. Superkey
B. Domain
C. Attribute
D. Schema

7. Minimal Superkeys are called
A. Schema keys
B. Candidate keys
C. Domain keys
D. Attribute keys

8. Which of the following is not Modification of the Database
A. Deletion
B. Insertion
C. Sorting
D. Updating

9. Which of the following is Relation-algebra Operation
A. Select
B. Union
C. Rename
D. All of the above

10. Which of the following in not Outer join?
A. Left outer join
B. Right outer join
C. Full outer join
D. All of the above
Answers
1 – A / 2 – C / 3 – B / 4 – A / 5 – C / 6 – A / 7 – B / 8 – C / 9 – D / 10 – D

1. Who proposed the relational model?
A. Bill Gates
B. E.F. Codd
C. Herman Hollerith
D. Charles Babbage

2. Set of premitted values of each attribute is called
A. Domain
B. Tuple
C. Relation
D. Schema

3. Which of the following in true regarding Null Value?
A. Null = 0
B. Null 0
D. Null 0

4. Logical design of database is called
A. Database Instance
B. Database Snapshot
C. Database Schema
D. All of the above

5. Snapshot of the dta in the database at a given instant of time is called
A. Database Schema
B. Database Instance
C. Database Snapshot
D. All of the above

6. Which of the following is not Unary operation?
A. Select
B. Project
C. Rename
D. Union

7. Which of the following is not binary operation?
A. Union
B. Project
C. Set Difference
D. Cartesian Product

8. Which of the following is correct regarding Aggregate functions?
A. it takes a list of values and return a single values as result
B. it takes a list of values and return a list of values as result
C. it takes a single value and returns a list of values as result
D. it takes a single value and returns a single value as result

9. The Primary key must be
A. Non Null
B. Unique
C. Option A or B
D. Option A and B

10. A command to remove a relation from an SQL database
A. Delete table <table name>
B. Drop table <table name>
C. Erase table <table name>
D. Alter table <table name>
Answers :-
1 – B / 2 – A / 3 – D / 4 – C / 5 – B / 6 – D / 7 – B / 8 – A / 9 – D / 10 – B

1. which of the following is not an Aggregate function?
A. Min
B. Max
C. Select
D. Avg

2. The attribute that can be divided into other attributes is called
A. Simple Attribute
B. Composite Attribute
C. Multi-valued Attribute
D. Derived Attribute

3. In an Entity-Relationship Diagram “Ellipses” represents
A. Attributes
B. Weak entity set
C. Relationship sets
D. Multi-valued attributes

4. In an Entity-Relationship Diagram “Diamonds” represents
A. Attributes
B. Multi-valued attributes
C. Weak entity set
D. Relationship sets

5. What is ACID properties of Transactions?
A. Atomicity, Consistency, Isolation, Database
B. Atomicity, Consistency, Isolation, Durability
C. Atomicity, Consistency, Inconsistent, Durability
D. Automatically, Concurrency, Isolation, Durability

6. If every non-key attribute is functionally dependent on the primary key, the relation will be in
A. First Normal Form
B. Second Normal Form
C. Third Normal Form
D. Fourth Formal Form

7. Database locking concept is used to solve the problem of
A. Lost Update
B. Uncommitted Dependency
C. Inconsistent Data
D. All of the above

8. UML is stands for
A. Universal Modeling Language
B. Unified Modeling Language
C. United Modeling Language
D. Uni Modeling Language

9. Data Manipulation Language (DML) is not to
A. Create information table in the Database
B. Insertion of new information into the Database
C. Deletion of information in the Database
D. Modification of information in the Database

10. Which of the following in true regarding Referential Integrity?
A. Every primary-key value must match a primary-key value in an associated table
B. Every primary-key value must match a foreign-key value in an associated table
C. Every foreign-key value must match a primary-key value in an associated table
D. Every foreign-key value must match a foreign-key value in an associated table
Answers :-
1 – C / 2 – B / 3 – A / 4 – D / 5 – B / 6 – C / 7 – D / 8 – B / 9 – A / 10 – C

1. Which of the following option is use to retrieval of data?
a. Stack
b. Data Structure
c. Linked list
d. Query

2. ODBC stands for ______
a. Offline database connection
b. Oriented database connection
c. Open database connection
d. None of above

3. Which algebra is widely used in DBMS?
a. Relational algebra
b. Arithmetic algebra
c. Both
d. None

4. Which of the following is an unary operation?
a. Selection operation
b. Generalized selection
c. Primitive operation
d. Projection operation

5. Which SQL Query is use to remove a table and all its data from the database?
a. Create Table
b. Alter Table
c. Drop Table
d. None of these

6. In precedence of set operators the expression is evaluated from:
a. Left to Left
b. Left to Right
c. Right to Right
d. Right to Left

7. In DBMS FD stands for _______
a. Facilitate data
b. Functional data
c. Facilitate dependency
d. Functional dependency

8. How many types of keys in Database Design?
a. Candidate key
b. Primary key
c. Foreign key
d. All of these

9. Which of the following is based on Multi Valued Dependency?
a. First
b. Second
c. Third
d. Fourth

10. Which of the following is the structure of the Database?
a. Table
b. Schema
c. Relation
d. None of these

Answers :-
1 – d / 2 – c / 3 – a / 4 – b / 5 – c / 6 – b / 7 – d / 8 – d / 9 – d / 10 – b

1. The minimal set of super key is called
A. Primary key
B. Secondary key
C. Candidate key
D. Foreign key

2. A relation that has no partial dependencies is in which normal form
A. First
B. Second
C. Third
D. BCNF

3. A functional dependency between two or more non-key attributes is called
A. Transitive dependency
B. Partial transitive dependency
C. Functional dependency
D. Partial functional dependency

4. A logical description of some portion of database that is required by a user to perform task is called as
A. System View
B. User View
C. Logical View
D. Data View

5. ______________ is a classical approach to database design?
A. Left – Right approach
B. Right – Left approach
C. Top – Down approach
D. Bottom – Up approach

6. _____________ refers to the correctness and completeness of the data in a database?
A. Data security
B. Data integrity
C. Data constraint
D. Data independence

7. A table that displays data redundancies yields ____________ anomalies
A. Insertion
B. Deletion
C. Update
D. All of the above

8. A lock that allows concurrent transactions to access different rows of the same table is known as a
A. Field-level lock
B. Row-level lock
C. Table-level lock
D. Database-level lock

9. A type of query that is placed within a WHERE or HAVING clause of another query is called
A. Super query
B. Sub query
C. Master query
D. Multi-query

10. A transaction completes its execution is said to be
A. Saved
B. Loaded
C. Rolled
D. Committed

Answers :-
1 – C / 2 – B / 3 – A / 4 – B / 5 – C / 6 – B / 7 – D / 8 – A / 9 – B / 10 – D
61.
When converting one (1) to many (N) binary relationship into tables, the recommended solution is usually
(a)
One big table with all attributes from both entities included
(b)
Foreign key added on the Child (many side) referencing the parent
(c)
Foreign key added on the Parent (one side) referencing the child
(d)
Foreign key added on both sides (both tables)
(e)
Primary Key is added on one side.
62.
Which of the following is not correct?
(a)
Each entity must include some descriptive information
(b)
If an object only requires an identifier, it should be classified as an attribute
(c)
Each multivalued attribute should be classified as an entity even if it does not have any descriptive information
(d)
The procedure of identifying entities and attaching attributes always leads to a unique solution
(e)
Every entity is a collection of attributes.
63.
The property of transaction which ensures that either all operations of the transaction are reflected properly in the database or none, is called
(a)
Atomicity
(b)
Durability
(c)
Isolation
(d)
Consistency
(e)
Deadlock.
64.
Which of the following is correct?
(a)
Function dependencies are not associated with relations; they are based on the semantics of information that we are dealing with
(b)
If a relation has no redundant information its attributes must not have any function dependencies
(c)
Functional dependencies may be determined if we are given several instances of a relation
(d)
The FDs that hold for attributes of a relation need not be satisfied at all times
(e)
BCNF is a fourth normal form.
65.
An entity type whose existence depends on another entity type is called a _____ entity.
(a)
Strong
(b)
Weak
(c)
Codependent
(d)
Variant
(e)
Independent.
66.
A property or characteristic of an entity type that is of interest to the organization is called an
(a)
Attribute
(b)
Coexisting entity
(c)
Relationship
(d)
Cross-function
(e)
Weak entity.
67.
A relationship between the instances of a single entity type is called a _____ relationship.
(a)
Ternary
(b)
Primary
(c)
Binary
(d)
Auxiliary
(e)
Unary.
68.
A ________ attribute is an attribute that can be further subdivided to yield additional attributes.
(a)
Composite
(b)
Simple
(c)
Single-valued
(d)
Multi-valued
(e)
Derived.
69.
In a super type/subtype hierarchy, each subtype has
(a)
Only one super type
(b)
Many super types
(c)
At most two super types
(d)
At least one subtype
(e)
Not at all.
70.
The hierarchical database model uses the hierarchic sequence that always starts at
(a)
The right side of the tree
(b)
The left side of the tree
(c)
The top of the tree
(d)
The bottom of the tree
(e)
Middle of the above.

Answers

61.
Answer : (b)
Reason: When converting one (1) to many (N) binary relationship into tables, the recommended solution is Foreign key added on the Child (many side) referencing the parent
62.
Answer : (d)
Reason: The procedure of identifying entities and attaching attributes always leads to a unique solution
63.
Answer : (a)
Reason: Atomicity is the property of transaction which ensures that either all operations of the transaction are reflected properly in the database or none
64.
Answer : (a)
Reason: Function dependencies are not associated with relations; they are based on the semantics of information that we are dealing with.
65.
Answer : (b)
Reason: Entity type whose existence depends on another entity type is called a weak entity
66.
Answer : (a)
Reason: A property or characteristic of an entity type that is of interest to the organization is called attribute
67.
Answer : (e)
Reason: A relationship between the instances of a single entity type is called a Unary relationship.
68.
Answer : (a)
Reason: Composite attribute is an attribute that can be further subdivided to yield additional attributes.
69.
Answer : (a)
Reason: In a super type/subtype hierarchy, each subtype has only one super type
70.
Answer : (b)
Reason: The hierarchical database model uses the hierarchic sequence that always starts at the left side of the tree

71.
Which of the following is a component of the relational data model included to specify business rules to maintain the integrity of data when they are manipulated?
(a)
Business rule constraint
(b)
Data integrity
(c)
Business integrity
(d)
Data structure
(e)
Entity Integrity.
72.
A null value is created or represented by
(a)
A zero
(b)
A space
(c)
Entering a value
(d)
Pressing the ESC key
(e)
Pressing the Enter key without making a prior entry of any kind.
73.
A functional dependency between two or more non-key attributes is called
(a)
Partial functional dependency
(b)
Partial non-key dependency
(c)
Transitive dependency
(d)
Partial transitive dependency
(e)
Key dependency.
74.
Which of the following is a classical approach to database design?
(a)
Top-down approach
(b)
Left-side approach
(c)
Right-side approach
(d)
Backwards approach
(e)
Middleware.
75.
In the context of a database table, the statement “A determines B” indicates that
(a)
Knowing the value of attribute A you can not look up the value of attribute B
(b)
You do not need to know the value of attribute A in order to look up the value of attribute B
(c)
Knowing the value of attribute B you can look up the value of attribute A
(d)
Knowing the value of attribute A you can look up the value of attribute B
(e)
None of the above.
76.
Which of the following Relational Algebra operations require that both tables (or virtual tables) involved have the exact same attributes/data types?
(a)
Join, Projection, Restriction
(b)
Multiplication and Division
(c)
Union, Intersection, Minus
(d)
Minus, Multiplication, Intersection
(e)
Projection, Selection, Rename.
77.
Which type of file is easiest to update?
(a)
Sequential
(b)
Hashed
(c)
Indexed
(d)
Clustered
(e)
Random.
78.
A method that speeds query processing by running a query at the same time against several partitions of a table using multi processors is called
(a)
Multiple partition query
(b)
Perpendicular query processing
(c)
Parallel query processing
(d)
Query optimization
(e)
Query Execution.
79.
The protocol that ensures conflict serializability is
(a)
Time stamp ordering protocol
(b)
Two phase locking protocol
(c)
Concurrency protocol
(d)
Tree protocol
(e)
Layered Protocol.
80.
Indexes are created in most RDBMS’s to
(a)
Provide a quicker way to store data
(b)
Decrease the amount of disk space utilized
(c)
Provide rapid, random and sequential access to base-table data
(d)
Increase the cost of implementation
(e)
Decrease the cost of implementation.

Answers

71.
Answer : (b)
Reason: Data integrity is a component of the relational data model included to specify business rules to maintain the integrity of data when they are manipulated
72.
Answer : (e)
Reason: A null value is created or represented by Pressing the Enter key without making a prior entry of any kind
73.
Answer : (c)
Reason: A functional dependency between two or more non-key attributes is called transitive dependency
74.
Answer : (a)
Reason: top-down approach is a classical approach to database design
75.
Answer : (d)
Reason: Knowing the value of attribute A you can look up the value of attribute B.
76.
Answer : (c)
Reason: n relational algebra Union, Intersection, Minus operations require that both tables (or virtual tables) involved have the exact same attributes/data types.
77.
Answer : (b)
Reason: Hash file is easiest to update
78.
Answer : (c)
Reason: A method that speeds query processing by running a query at the same time against several partitions of a table using multi processors is called parallel query processing.
79.
Answer : (a)
Reason: The protocol that ensures conflict serializability is time stamp ordering protocol.
80.
Answer : (c)
Reason: Indexes are created in most RDBMS’s to Provide rapid, random and sequential access to base-table data
DATABASE MANAGEMENT SYSTEM SET 9

Database Management System
Questions 81 To 90
81.
What does the following SQL statement do?
Select * From Customer Where Cust_Type = “Best”;
(a)
Selects all the fields from the Customer table for each row with a customer labeled “best”
(b)
Selects the “*” field from the Customer table for each row with a customer labeled “best”
(c)
Selects fields with a “*” in them from the Customer table
(d)
Selects all the fields from the Customer table for each row with a customer labeled “*”
(e)
Counts all records and displays the value.
82.
In an SQL statement, which of the following parts states the conditions for row selection?
(a)
Select
(b)
From
(c)
Order By
(d)
Group By
(e)
Where.
83.
Which of the following questions is answered by the SQL statement?
Select Count (Product_Description) from Product_T;
(a)
How many products are in the Product Table?
(b)
How many different product descriptions are in the Product Table?
(c)
How many characters are in the field name “Product_Description”?
(d)
How many different columns named “Product Description” is there in table Product_T?
(e)
How many total records in a table?
84.
All of the following are advantages of SQL-invoked routines EXCEPT
(a)
Flexibility
(b)
Efficiency
(c)
Sharability
(d)
Security
(e)
Easy of use.
85.
A type of query that is placed within a WHERE or HAVING clause of another query is called
(a)
Master query
(b)
Sub query
(c)
Super query
(d)
Multi-query
(e)
Co-related query.
86.
Which of the following is a procedure for acquiring the necessary locks for a transaction where all necessary locks are acquired before any are released?
(a)
Record controller
(b)
Exclusive lock
(c)
Authorization rule
(d)
Two phase lock
(e)
Three Phase lock.
87.
Out of the following activities, which is the one that normally performed by DBMS, without the interference of the DBA?
(a)
Integrity
(b)
Retention
(c)
Security
(d)
Granting the Privileges
(e)
Recovery.
88.
Horizontal Fragmentation is
(a)
Divide the data up by logical groups of records
(b)
Divide the data up by logical groups of attributes
(c)
Divide the data up by logical groups of entities
(d)
Divide the data up by logical groups of files
(e)
Divide the data up by logical frames.
89.
An index record appears for every search key value in the file is
(a)
Secondary index
(b)
Dense index
(c)
Sparse index
(d)
Multi level index
(e)
B+ tree.
90.
Which of the following type of index is automatically created when we do not specify?
(a)
Bitmap
(b)
Balanced Tree Index
(c)
Binary Tree Index
(d)
Hashed
(e)
Sparse Index.

Answers
81.
Answer : (a)
Reason: Select
82.
Answer : (e)
Reason: In an SQL statement where clause states the conditions for row selection
83.
Answer : (b)
Reason: How many different product descriptions are in the Product Table?
84.
Answer : (d)
Reason: Security
85.
Answer : (b)
Reason: Sub-query that is placed within a WHERE or HAVING clause of another query
86.
Answer : (d)
Reason: Two-phase lock is a procedure for acquiring the necessary locks for a transaction where all necessary locks are acquired before any are released
87.
Answer : (e)
Reason: Recovery is the one that normally is performed by DBMS, without the interference of the DBA
88.
Answer : (a)
Reason: Divide the data up by logical groups of records.
89.
Answer : (b)
Reason: Dense Index record appears for every search key valued in the file.
90.
Answer : (b)
Reason: Balanced Tree Index is automatically created when we do not specify.

91.
A database management software (DBMS) includes
(a)
Automated tools (CASE) used to design databases and application programs
(b)
A software application that is used to define, create, maintain and provide controlled access to user databases
(c)
Application programs that are used to provide information to users
(d)
Database that contains occurrences of logically organised data or information
(e)
Repository of meta data, which is a central storehouse for all data definitions, data relationships,
screen and report formats and other system components.
92.
Making a change to the conceptual schema of a database but not affecting the existing external schemas is an example of
(a)
Physical data independence
(b)
Concurrency Control
(c)
Logical data independence
(d)
Functional dependency
(e)
Integrity Control.
93.
If K is a foreign key in a relation R1, then
(a)
Every tuple of R1 has a distinct value for K
(b)
K cannot have a null value for tuples in R1
(c)
K is a key for some other relation
(d)
K is a Primary key for R1
(e)
K is a Composite key for R1.
94.
Which of the following concept is applicable with respect to 2NF?
(a)
Full functional dependency
(b)
Partial dependency
(c)
Transitive dependency
(d)
Non-transitive dependency
(e)
Data independence.

95. State the unit of storage that can store one or more records in a hash file organization
(a)
Buckets
(b)
Disk pages
(c)
Blocks
(d)
Nodes
(e)
Baskets.

96.
Embedded SQL means
(a)
Using the EMBED key word in a SQL statement
(b)
Writing a SQL statement to retrieve data from more than one relation
(c)
Writing SQL statements within codes written in a general programming language
(d)
Specifying a condition and action to be taken in case the given condition is satisfied in a trigger
(e)
Using SQL language constructs like revoke and grant respectively for revoking and granting privileges to users.
97.
“In 1978 committee proposed a generalized framework for database systems and it provides a three_level architecture. The of the architecture defines user views of the database. The defines the physical view of the database. The defines the logical schema of the database.”
Which of the following set is suitable to fill the blanks in the above paragraph?
(a)
i. ANSI/ARPANET
ii. Conceptual Level
iii. External Level
iv. Internal Level
(b)
i. ANSI/SPARC
ii. Conceptual Level
iii. External Level
iv. Internal Level
(c)
i. .ANSI/ARPANET
ii. External Level
iii. Internal Level
iv. Conceptual Level
(d)
i. ANSI/SPARC
ii. External Level
iii. Internal Level
iv. Conceptual Level
(e)
i. W3C
ii. Internal Level
iii. External Level
iv. Conceptual Level.
98.
Consider the following ER diagram depicting the relationship of an employee and supervisor:

What is the possible relation if the above ERD is mapped into a relational model?
(a)
Employee (EmpID, BirthDate, Salary, Name(FirstName, MiddleName, LastName))
(b)
Employee (EmpID, BirthDate, Salary, Name(FirstName, MiddleName, LastName)}
(c)
Supervision (EmpID, BirthDate, Salary, Name(FirstName, MiddleName, LastName), EmpID)
(d)
Supervisor (SupervisorID, BirthDate, Salary, Name(FirstName, MiddleName, LastName),EmpID), {EmpID})
(e)
Employee (EmpID, BirthDate, Salary, Name(FirstName, MiddleName, LastName), SupervisorID).
99.
Select the correct statement from the following on proper naming of schema constructs:
(a)
Entity type name applies to all the entities belonging to that entity type and therefore a plural name is selected for entity type
(b)
In the narrative description of the database requirements, verbs tend to indicate the names of
relationship types
(c)
The nouns arising from a database requirement description can be considered as names of attributes
(d)
Additional nouns which are appearing in the narrative description of the database requirements
represent the weak entity type names
(e)
Adjectives written in the database requirement description help to identify the partial relationships among entities.
100.
Consider the following table obtained using Student and Instructor relations.
Fname :
Ajith
Sujith
Kasun

Lname :
Gamage
Hewage
Peiris
Which relational algebra operation could have been applied on the pair of relations Student and Instructor to obtain the above data?
(a)
Student n Instructor
(b)
Instructor ÷ Student
(c)
Student – Instructor
(d)
Student ? Instructor
(e)
Instructor – Student.

Answers

91.
Answer : (b)
Reason : A software application that is used to define, create, maintain and provide controlled access to user databases.
92.
Answer : (c)
Reason : Logical data independence refers to making a change to the conceptual schema of a database but not affecting the existing external schemas.
93.
Answer : (c)
Reason : If k is a foreign key in a relation R1, then K is a key for some other relation.
94.
Answer : (a)
Reason : Full functional dependency is applicable with respect to 2NF.
95.
Answer : (a)
Reason : Buckets are used to store one or more records in a hash file organization.
96.
Answer : (c)
Reason : Embedded SQL refers to writing SQL statements within codes written in a general programming language.
97.
Answer : (d)
Reason : i).ANSI/SPARC ii) External Level iii)Internal Level iv) Conceptual Level
98.
Answer : (e)
Reason : Employee(EmpID, BirthDate, Salary, Name(FirstName, MiddleName, LastName),SupervisorID) is the possible relation if the given ERD is mapped into a relational data model.
99.
Answer : (b)
Reason : In the narrative description of the database requirements, verbs tend to indicate the names of relationship types.
100.
Answer : (e)
Reason : Instructor – Student is the relational algebra operation that could be applied on the pair of relations Student and Instructor to obtain the above data.

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