Important Data Base Management Science Set 3

Read important Data Base Management Science MCQS For Exam.These General Knowledge Mcqs Contain  of World technology,  Science & Literature, events Mcqs, Data Base Management Science Mcqs and International Organizations. These general knowledge questions are very important for all type of exams.
Note: The bold option is the right answer for the given MCQ’S:


1. In an object-oriented model, one object can access
data of another object by passing:
a. Instance variable
b. Message
c. Variable
d. None of these

2. A view of database that appears to an application
program is known as:
a. Schema
b. Subschema
c. virtual table
d. none of the above

3. An abstraction concept for building composite
object from their component object is called:
a. Specialization
b. Normalization
c. Generalization
d. Aggregation

4. A set of objects that share a common structure and
a common behavior is called:
a. Object
b. Class
c. Entity
d. None of these

5. Every weak entity set can be converted into a
strong entity set by:
a. using generalization
b. adding appropriate attributes
c. using aggregation
d. none of the above

6. The number of entities to which another entity can
be associated via a relationship set is expressed
a. Entity
b. Cardinality
c. Schema
d. Attributes

7. Relations produced from an E-R model will always be
a. First normal form
b. Second normal form
c. Third normal form
d. Fourth normal form

8. In ER model the details of the entities are hidden
from the user. This process is called:
a. Generalization
b. Specialization
c. Abstraction
d. none of these above

9. The file organization that provides very fast
access to any arbitrary record of a file is:
a. Ordered file
b. Unordered file
c. Hashed file
d. B-tree

10. What is not true about a view?
a. It is a definition of a restricted portion of
the database
b. It is a security mechanism
c. It is always updatable like any other table
d. All are true

11. In a relational database a referential integrity
constraint can be specified with the help of
a. primary key
b. foreign key
c. secondary key
d. none of the above

12. A super key is a set of one or more attributes
that, taken collectively, allow us
a. to identify uniquely an entity in the entity
b. to make the key most powerful for faster
c. to increase effectiveness of database access
d. none of the above

13. 4NF is designed to cope with:
a. Transitive dependency
b. Join dependency
c. Multi valued dependency
d. None of these

14. Every Boyee-Codd normal form is in
a. First normal form
b. Second normal form
c. Third normal form
d. All of the above

15. Which command is used to remove all rows from a
a. Delete
b. Remove
c. Truncate

d. Both [A] and [B]

16. Which of the following is an aggregate function in
a. Union
b. Like
c. Group By
d. Max

17. Which command is used to add a column to an
existing table?
a. Create

b. Update

d. None of these
18. A deadlock exists in the system if and only if the
wait for graph:
a. has a cycle in it
b. has a path from first node to last node
c. is a tree
d. none of the above

19. Rollback of transactions is normally used to:
a. recover from transaction failure
b. update the transaction
c. retrieve old records
d. repeat a transaction

20. Prevention of access to the database by
unauthorized users is referred to as

a. Integrity

b. Productivity
b. Security

d. Reliability

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