Database Management System Set 26

Database Management System

Questions 251 to 260



251.
If K is a foreign key in 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.
252.
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)  None of the above.
253.
Any set of attributes that uniquely identifies each table in a relation is termed as
(a)  Foreign key       (b)  Primary key       (c)  Super key          (d)  Candidate key         (e)  Unique.
254.
What SQL is a set of statements that allows SQL to be used with traditional programming languages
(a)  Common SQL    (b)  Embedded        (c)  SEQUEL          
(d)  QBE                 (e)  QUEL.
255.
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.
256.
In a relationship, when a primary key from one table is also defined in a second table, what is the name of the field is referred to in the second table.
(a)  Combined Key                                 (b)  Redundant field                       (c)  Primary key
(d)  Foreign key                                     (e)  Candidate Key.
257.
What constraints maintain uniqueness in a record?
(a)  Entity integrity   (b)  Referential Integrity                          (c)  Domain Integrity
(d)  Check integrity  (e)  NULL.
258.
What is a predicate expressing a condition that always must be satisfied?
(a)  Assertion                                         (b)  Trigger                                       (c)  Procedure
(d)  Function                                          (e)  Generalization.
259.
What is the name of the operator in a relation that yields values from all rows in a table?
(a)  Difference         (b)  Product             (c)  Select               (d)  Project              (e)  Join.
260.
Which of the following concepts is applicable with respect to 2NF?
(a)  Full functional dependency               (b)  Partial dependency                         
(c)  Transitive dependency                      (d)  Non-transitive dependency              
(e)  Data independence.

Answers


251.
Answer : (c)
Reason:  If K is a foreign key in relation R1, then K is a key for some other relation.
252.
Answer : (a)
Reason:  Top-down approach.
253.
Answer : (c)
Reason:  super key.
254.
Answer : (b)
Reason:  Embedded SQL is set of SQL statements and traditional programming language.
255.
Answer : (d)
Reason:  Knowing the value of attribute A you can look up the value of attribute B.
256.
Answer : (d)Reason:     Foreign key.
257.
Answer : (a)
Reason:  Entity Integrity constraints maintains uniqueness in a record.
258.
Answer : (a)
Reason:  Assertion is predicate expressing a condition that always must be satisfied.
259.
Answer : (c)
Reason:  Select operator in a relation  that yields values from all rows in a table.
260.
Answer : (a)
Reason:  Full functional dependency.


<< Prev  1...  2...  3...  4...  5...  6...  7...  8...  9...  10...  11...  12...  13...  14...  15...  16...  17...  18...  19...  20...  21...  22...  23...  24...  25...  26...  27...  28...  29...  30...  31...  32...  33...  34...  35...  36...  Next >>


1 comment :