DBMS MCQ SET 3


  1. In the __________ normal form, a composite attribute is converted to individual attributes.
    A) First
    B) Second
    C) Third
    D) Fourth

Answer:A
Explanation: The first normal form is used to eliminate the duplicate information.


  1. A table on the many side of a one to many ormany to many relationship must:
    a) Be in Second Normal Form (2NF)
    b) Be in Third Normal Form (3NF)
    c) Have a single attribute key
    d) Have a composite key

Answer:D
Explanation: The relation in second normal form is also in first normal form and no partial dependencies on any column in primary key.


  1. Tables in second normal form (2NF):
    a) Eliminate all hidden dependencies
    b) Eliminate the possibility of a insertion anomalies
    c) Have a composite key
    d) Have all non key fields depend on the whole primary key

Answer:A
Explanation: The relation in second normal form is also in first normal form and no partial dependencies on any column in primary key.


  1. Which-one of the following statements about normal forms is FALSE?
    a) BCNF is stricter than 3 NF
    b) Lossless, dependency -preserving decomposition into 3 NF is always possible
    c) Loss less, dependency – preserving decomposition into BCNF is always possible
    d) Any relation with two attributes is BCNF

Answer:C
Explanation: We say that the decomposition is a lossless decomposition if there is no loss of information by replacing r (R) with two relation schemas r1(R1) andr2(R2).


  1. Functional Dependencies are the types of constraints that are based on______
    a) Key
    b) Key revisited
    c) Superset key
    d) None of these

Answer:A
Explanation: Key is the basic element needed for the constraints.


  1. Which is a bottom-up approach to database design that design by examining the relationship between attributes:
    a) Functional dependency
    b) Database modeling
    c) Normalization
    d) Decomposition

Answer:C
Explanation: Normalisation is the process of removing redundancy and unwanted data.


  1. Which forms simplifies and ensures that there is minimal data aggregates and repetitive groups:
    a) 1NF
    b) 2NF
    c) 3NF
    d) All of the mentioned

Answer:C
Explanation: The first normal form is used to eliminate the duplicate information.


  1. Which forms has a relation that possesses data about an individual entity:
    a) 2NF
    b) 3NF
    c) 4NF
    d) 5NF

Answer:C
Explanation: A Table is in 4NF if and only if, for every one of its non-trivial multivalued dependencies X \twoheadrightarrow Y, X is a superkey—that is, X is either a candidate key or a superset thereof.


  1. Which forms are based on the concept of functional dependency:
    a) 1NF
    b) 2NF
    c) 3NF
    d) 4NF

Answer:C
Explanation: The table is in 3NF if every non-prime attribute of R is non-transitively dependent (i.e. directly dependent) on every superkey of R.


  1. Empdt1(empcode, name, street, city, state,pincode).
    For any pincode, there is only one city and state. Also, for given street, city and state, there is just one pincode. In normalization terms, empdt1 is a relation in
    a) 1 NF only
    b) 2 NF and hence also in 1 NF
    c) 3NF and hence also in 2NF and 1NF
    d) BCNF and hence also in 3NF, 2NF and 1NF

Answer:B
Explanation: The relation in second normal form is also in first normal form and no partial dependencies on any column in primary key.


 

1.) Which type of file is part of the Oracle database?

A.)     Control file

B.)     Password file

C.)     Parameter files

D.)     Archived log files

 

Answer: Option A


2.) Which statements are use to UNLOCK the user?

A.)     Alter user Scott account lock;

B.)     Modified user Scott account unlock;

C.)     Alter user Scott account unlock;

D.)     Alter user Scott unlock

 

Answer: Option C


3.) For which two constraints are indexes created when the constraint is added?

A.)   Check

B.)   Unique

C.)   Not null

D.)   Primary key

E.)   Foreign key

 

Answer: Option B, D


4.) What type of failure occurs when Oracle fails due to an operating system or computer hardware failure?

A.)     Application failure

B.)     Instance Failure

C.)     Media Failure

D.)     Rollback failure

 

Answer: Option B


5.) What Oracle backup and recovery file contains user and system data?

A.)     Control file

B.)     Datafile

C.)     OnLine ReDo file

D.)     Offline ReDo file

 

Answer:  Option  B


6.) When is the SGA created in an Oracle database environment?

A.)   When the database is created

B.)   When a user process is started

C.)   When the database is mounted

D.)   When the instance is started

E.)    When a server process is started

 

Answer:  Option   D


7.) Which password management feature ensures a user cannot reuse a password for a specified time interval?

A.)   Account Locking

B.)   Password History

C.)   Password Verification

D.)  Password Expiration and Aging

 

Answer:  Option  B


8.) Which privilege is required to create a database?

A.)   SYSDBA

B.)   DBA

C.)   SYSOPER

D.)   RESOURCE

 

Answer:    Option   A


9.) What is the type of Oracle backup in which all uncommitted changes have been removed from the datafiles?

A.)     Full backup

B.)     Consistent backup

C.)     Inconsistent backup

D.)     Differential backup

    

Answer:   Option    B


10.) Which three are the physical structures that constitute the Oracle database? (Choose three.)

A.)   Table

B.)   Extent

C.)   Segment

D.)   Data file

E.)    Log file

F.)    Tablespace

G.)   Control file

Answer:   Option  D,  E,  G


 

11.) What is the maximum size of the page ?

A.)     Characters wide & 265 characters length
B .)     Characters wide & 265 characters length
C .)     Characters wide & 80 characters length
D .)     None of the above

Answer:    Option  B


12.) Relational calculus is a

  1. A) Procedural language.
  2. B) Non- Procedural language.
  3. C) Data definition language.
  4. D) High level language.

 

Answer:    Option  B


13.) The view of total database content is

  1. A)      Conceptual view.
  2. B)      Internal view.
  3. C)      External view.
  4. D)      Physical View.

   Answer:  Option  A


14.) DML is provided for

  1. A)      Description of logical structure of database.
  2. B)      Addition of new structures in the database system.
  3. C)      Manipulation & processing of database.
  4. D)      Definition of physical structure of database system.

 

Answer:  Option  C


15.) ‘AS’ clause is used in SQL for

  1. A)      Selection operation.
  2. B)      Rename operation.
  3. C)      Join operation.
  4. D)      Projection operation.

 

Answer:  Option  B


16.) ODBC stands for

  1. A)      Object Database Connectivity.
  2. B)      Oral Database Connectivity.
  3. C)      Oracle Database Connectivity.
  4. D)      Open Database Connectivity.

 

Answer:  Option  D


17.) In the architecture of a database system external level is the

  1. A)      Physical level.
  2. B)      Logical level.
  3. C)      Conceptual level
  4. D)      View level.

 

Answer:  Option   D


18.) In an E-R diagram attributes are represented by

  1. A)      rectangle.
  2. B)      Square.
  3. C)      Ellipse.
  4. D)      Triangle.

  

Answer:  Option   C


19.) A logical schema

  1. A) Is the entire database.
  2. B) Is a standard way of organizing information into accessible parts?
  3. C) Describes how data is actually stored on disk.
  4. D) Both (A) and (C)

 

Answer:  Option  A


20.) The database environment has all of the following components except:

  1. A) Users.
  2. B) Separate files.
  3. C) Database.
  4. D) Database administrator

 

Answer:   Option  A