Database Management Systems Set 34

Database Management Systems

Questions  331 to 340



331.
What are “Raw” facts such as telephone number, birth date, sales value etc are called?
(a) Record                     (b) Data                         (c) File                            (d) Field (e) Information
332.
Which of the following models is concerned with what is represented in the database, rather than how it is represented?
(a) Conceptual model                                         (b) View model             (c) Physical model     
(d) External model                                               (e) Implementation model.
333.
Which of the following is not a component of storage manager?
(a) Authorization and integrity manager         (b) Transaction manager
(c) File manager                                                    (d) Buffer manager     (e) Query evaluation engine.
334.
Which of the following specifies that an entity can be a member of only one subtype at a time?
(a) Removal                  (b) Exclusion                 (c) Disjoint                     (d) Inclusion (e) Overlapping.
335.
For the following diagram, which answer is true?

(a)    Each employee can supervise 1 to many employees
(b)    Each employee can manage many departments
(c)     Each employee works in one department
(d)    Both (a) and (b) above
(e)     Both (a) and (c) above.
336.
Which of the following is the relationship between two instances of a single or same entity type?
(a) Binary                      (b) Tertiary                    (c) Primary                    (d) Ternary                    (e) Unary.
337.
On which of the following options the Hierarchical database model is based?
(a) Tree structure                 (b) Graph structure
(c) Relational model                                            (d) Physical model
(e) Linear lists.
338.
Which of the following options depicts the organization of data in a relational database?
(a) A collection of records                                  (b) A collection of common fields
(c) Elements                                                          (d) Tables                                                               (e) Objects.
339.
Which of the following relational operations yields all values from selected attributes?
(a) Difference               (b) Product                    (c) Select                        (d) Project                      (e) Join.
340.
Consider the relation pt_works(emp_name, branch_name, salary):
Which of the following is the correct relational algebra expression for finding the maximum salary for part-time employees at each branch?
(a) branch_name g max(salary)                           (b) branch_name g max(salary) (pt_works)
(c) g max (salary) (pt_works)                      (d) branch_name g sum(salary) (pt_works)
(e) branch_name G max(salary) (pt_works).


Answers

331.
Answer :   (b)
Reason :   “Raw” facts are called data.
332.
Answer :   (a)
Reason :   Conceptual model is concerned with the logical details(what is represented ) of the database.
333.
Answer :   (e)
Reason :   Query evaluation is not a part of the strorage manager.It is a pat of the query processor.
334.
Answer :   (c)
Reason :   Disjoint rule is a constraint of specialiazation.
335.
Answer :   (e)
Reason :   Both a and c are correct.
336.
Answer :   (e)
Reason :   A relationship between the instances of a single entity type is called a unary relationship.
337.
Answer :   (a)
Reason :   The Hierarchical database model is based on tree structure.
338.
Answer :   (d)
Reason :   In a relational database data is organized as tables.
339.
Answer :   (c)
Reason :   A Relational operator that yields all values from selected attributes is known as a select operator.
340.
Answer :   (b)
Reason :   brach_name g max(salary) (pt_works) is the correct syntax.

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