MIDTERM EXAMINATION CS403- Database Management Systems Fall 2008

Question No: 1    ( Marks: 1 )    - Please choose one

 Which of the following is not a benefit of normalization?

       ► Minimize insertion anomolies

       ► Minimize deletion anomolies

       ► Minimize updation anomolies

       ► Maximize redundancy

   

Question No: 2    ( Marks: 1 )    - Please choose one

 Which of the following is NOT a component of a DFD?

       ► Dataflow

       ► Datastore

       ► External entities

       ► Relationship between external entities

   

Question No: 3    ( Marks: 1 )    - Please choose one

 Which of the following is correct regarding Dataflow diagram?

       ► Single DFD is required to represent a system

       ► The dataflow must be bidirectional

       ► Created at increasing levels of detail

       ►       Used to represent the relationships among the external entities

   

Question No: 4    ( Marks: 1 )    - Please choose one

 Which of the following is CORRECT about database management system's languages?

       ► Data definition languages are used to specify the conceptual schema only.

       ► Data manipulation languages are used to create the databases.

       ► Data manipulation languages are used for retrieval, insertion, deletion and modification of data.

       ► Data definition langauges are only used to update data in the DBMS.

   

Question No: 5    ( Marks: 1 )    - Please choose one

 Controlling redundancy in a database management system DOES NOT help to

       ► avoid duplication

       ► avoid unnecessary wastage of storage space

       ► avoid unauthorised access to data

       ► avoid inconsistency among data

   

Question No: 6    ( Marks: 1 )    - Please choose one

 Which of the following concepts is applicable with respect to 3NF?

       ► Full functional dependency

       ► Any kind of dependency

       ► Transitive dependency

       ► Partial functional dependency

   

Question No: 7    ( Marks: 1 )    - Please choose one

 Consider two sets A and B. A contains 3 elements and B contains 4. How many elements do their cartesian product contains?

       ► 12

       ► 9

       ► 16

       ► 7

   

Question No: 8    ( Marks: 1 )    - Please choose one

 Consider two sets A and B. A contains 2 elements and B contains 3. How many elements do their cartesian product contains?

       ► 6

       ► 9

       ► 4

       ► 5

   

Question No: 9    ( Marks: 1 )    - Please choose one

 In a conceptual database model, which of the following most likely represents a valid identifier for a class grades?

       ► StudentID

       ► StudentID, CourseID

       ► StudentID, CourseID, InstructorID

       ► StudentID, CourseSectionID

   

Question No: 10    ( Marks: 1 )    - Please choose one

 Identify the correct statement with respect to normalization.

       ► Normalization is a formal technique that can be used only at the starting phase of the database design.

       ► Normalization can be used as a top-down standalone database design technique.

       ► The process of normalization through decomposition must achieve the lossless join

property at any cost whereas the dependency reservation property is sometimes

sacrificed.

       ► The process of normalization through decomposition must achieve the dependency

reservation property at any cost whereas the lossless join property is sometimes

sacrificed.

   

Question No: 11    ( Marks: 1 )    - Please choose one

 Consider the following relation and its sample data. (Consider that these are the only tuples for the given relation)

Which of the following statements is NOT correct?

       ► The functional dependency DeptNo -> ProjNo holds over R.

       ► The functional dependency EmpNo -> DeptNo holds over R.

       ► The functional dependency ProjNo -> DeptNo holds over R.

       ► The functional dependency (EmpNo, ProjNo) -> DeptNo holds over R.

   

Question No: 12    ( Marks: 1 )    - Please choose one

 Which of the following is not true about relational tables?

       ► Column values are of the same kind.

       ► Each row is unique.

       ► Each column must have a unique name.

       ► The sequence of rows is significant.

   

Question No: 13    ( Marks: 1 )    - Please choose one

 Identify the operation which is NOT one of the parts of the five basic set operations in relational algebra?

       ► Join

       ► Union

       ► Cartesian Product

       ► Set Difference

   

Question No: 14    ( Marks: 1 )    - Please choose one

 Consider the following statements.

A. An entity integrity constraint states that no primary key value can be null.

B. A referential integrity constraint is specified between two relations.

C. A foreign key cannot be used to refer to its own relation.

Identify which of the above statements is/are correct.

       ► Only A

       ► Only B

       ► Only B and C

       ► Only A and B

   

Question No: 15    ( Marks: 1 )    - Please choose one

 If K is a foreign key in relation R1, then

       ► every tuple of R1 has a distinct value for K.

       ► K cannot have a null value for tuples in R1.

       ► K is a  key for some other relation.

       ► K is a primary key for R1.

   

Question No: 16    ( Marks: 1 )    - Please choose one

 Making a change to the conceptual schema of a database but not affecting the existing external schemas is an example of

       ► Physical data independence.

       ► Concurrency control.

       ► Logical data independence.

       ► Functional dependency

   

Question No: 17    ( Marks: 1 )

 In which condition a relation in first normal form, automatically turns into the second normal form?

   

Question No: 18    ( Marks: 1 )

 State one limitation of Data flow diagrams

   

Question No: 19    ( Marks: 2 )

 What do you know about Insertion anomaly?

   

Question No: 20    ( Marks: 3 )

 What do you know about the conceptual view of database?

   

Question No: 21    ( Marks: 5 )

 Explain the purpose of defining processing rights for a database.

   

Question No: 22    ( Marks: 10 )

 Explain and differentiate between Context Level and Level 0 dataflow diagrams.