1. OLAP stands for
a) Online analytical
processing
b) Online analysis
processing
c) Online transaction
processing
d) Online aggregate
processing
View Answer
Answer: a
Explanation: OLAP is the manipulation of information to
support decision making .
2. Data that can be
modeled as dimension attributes and measure attributes are called _______ data.
a) Multidimensional
b) Singledimensional
c) Measured
d) Dimensional
View Answer
Answer: a
Explanation: Given a relation used for data analysis, we
can identify some of its attributes as measure attributes, since they measure
some value, and can be aggregated upon.Dimension attribute define the
dimensions on which measure attributes, and summaries of measure attributes,
are viewed.
3. The generalization
of cross-tab which is represented visually is ____________ which is also called
as data cube.
a) Two dimensional
cube
b) Multidimensional
cube
c) N-dimensional cube
d) Cuboid
View Answer
Answer: a
Explanation: Each cell in the cube is identified for the
values for the three dimensional attributes.
4. The process of
viewing the cross-tab (Single dimensional) with a fixed value of one attribute
is
a) Slicing
b) Dicing
c) Pivoting
d) Both Slicing and
Dicing
View Answer
Answer: a
Explanation: The slice operation selects one particular
dimension from a given cube and provides a new sub-cube. Dice selects two or
more dimensions from a given cube and provides a new sub-cube.
5. The operation of
moving from finer-granularity data to a coarser granularity (by means of
aggregation) is called a ________
a) Rollup
b) Drill down
c) Dicing
d) Pivoting
View Answer
Answer: a
Explanation: The opposite operation—that of moving
fromcoarser-granularity data to finer-granularity data—is called a drill down.
6. In SQL the
cross-tabs are created using
a) Slice
b) Dice
c) Pivot
d) All of the
mentioned
View Answer
Answer: a
Explanation: Pivot (sum(quantity) for color in
(’dark’,’pastel’,’white’)) .
7.
{ (item name, color,
clothes size), (item name, color), (item name, clothes size), (color, clothes
size), (item name), (color), (clothes size), () }
This can be achieved
by using which of the following ?
a) group by rollup
b) group by cubic
c) group by
d) none of the
mentioned
View Answer
Answer: d
Explanation: ‘Group by cube’ is used .
8. What do data
warehouses support?
a) OLAP
b) OLTP
c) OLAP and OLTP
d) Operational
databases
View Answer
Answer: a
Explanation: None .
9.
SELECT item name,
color, clothes SIZE, SUM(quantity)
FROM sales
GROUP BY rollup(item
name, color, clothes SIZE);
How many grouping is
possible in this rollup?
a) 8
b) 4
c) 2
d) 1
View Answer
Answer: b
Explanation: { (item name, color, clothes size), (item
name, color), (item name), () } .
10. Which one of the
following is the right syntax for DECODE ?
a) DECODE (search,
expression, result [, search, result]… [, default])
b) DECODE
(expression, result [, search, result]… [, default], search)
c) DECODE (search,
result [, search, result]… [, default], expression)
d) DECODE
(expression, search, result [, search, result]… [, default])
View Answer
Answer: d
Explanation: None.
1. Relational Algebra
is a __________ query language that takes two relation as input and produces
another relation as output of the query.
a) Relational
b) Structural
c) Procedural
d) Fundamental
View Answer
Answer: c
Explanation: This language has fundamental and other
operations which are used on relations .
2. Which of the
following is a fundamental operation in relational algebra ?
a) Set intersection
b) Natural join
c) Assignment
d) None of the
mentioned
View Answer
Answer: d
Explanation: The fundamental operations are select,
project, union, set difference, Cartesian product, and rename.
3. __Which of the
following is used to denote the selection operation in relational algebra ?
a) Pi (Greek)
b) Sigma (Greek)
c) Lambda (Greek)
d) Omega (Greek)
View Answer
Answer: b
Explanation: The select operation selects tuples that
satisfy a given predicate.
4. For select
operation the ________ appear in the subscript and the ___________ argument
appears in the paranthesis after the sigma.
a) Predicates,
relation
b) Relation,
Predicates
c) Operation,
Predicates
d) Relation,
Operation
View Answer
Answer: a
Explanation: None.
5. The ___________
operation, denoted by −, allows us to find tuples that are in one relation but
are not in another.
a) Union
b) Set-difference
c) Difference
d) Intersection
View Answer
Answer: b
Explanation: The expression r − s produces a relation
containing those tuples in r but not in s.
6. Which is a unary
operation:
a) Selection
operation
b) Primitive
operation
c) Projection
operation
d) Generalized
selection
View Answer
Answer: d
Explanation: Generalization Selection takes only one
argument for operation.
7. Which is a join
condition contains an equality operator:
a) Equijoins
b) Cartesian
c) Natural
d) Left
View Answer
Answer: a
Explanation: None.
8. In precedence of
set operators the expression is evaluated from
a) Left to left
b) Left to right
c) Right to left
d) From user
specification
View Answer
Answer: b
Explanation: The expression is evaluated from left to
right according to the precedence.
9. Which of the
following is not outer join ?
a) Left outer join
b) Right outer join
c) Full outer join
d) All of the
mentioned
View Answer
Answer: d
Explanation: The FULL OUTER JOIN keyword combines the
result of both LEFT and RIGHT joins.
10. The assignment operator
is denoted by
a) ->
b) <-
c) =
d) ==
View Answer
Answer: b
Explanation: The result of the expression to the right of
the ← is assigned to the relation variable on the left of the ←.
1. Find the ID, name,
dept name, salary for instructors whose salary is greater than $80,000 .
a) {t | t ε
instructor ∧ t[salary] > 80000}
b) Ð t ∈
r (Q(t))
c) {t | Рs ε
instructor (t[ID] = s[ID]∧ s[salary] > 80000)}
d) None of the
mentioned
View Answer
Answer: a
Explanation: This expression is in tuple relational format.
2. A query in the
tuple relational calculus is expressed as:
a) {t | P() | t}
b) {P(t) | t }
c) {t | P(t)}
d) All of the
mentioned
View Answer
Answer: c
Explanation: The tuple relational calculus, is a
nonprocedural query language. It describes the desired information without
giving a specific procedure for obtaining that information.
3.
{t | Э s
ε instructor (t[name] = s[name]
∧Э
u ε department (u[dept name] = s[dept name]
∧ u[building] = “Watson”))}
Which of the
following best describes the query ?
a) Finds the names of
all instructors whose department is in the Watson building.
b) Finds the names of
all department is in the Watson building.
c) Finds the name of
the dapartment whose instructor and building is Watson.
d) Returns the
building name of all the departments.
View Answer
Answer: a
Explanation: This query has two “there exists” clauses in
our tuple-relational-calculus expression, connected by and (∧).
4. Which of the
following symbol is used in the place of except ?
a) ^
b) V
c) ¬
d) ~
View Answer
Answer: c
Explanation: The query ¬P negates the value of P .
5. “Find all students
who have taken all courses offered in the Biology department.” The expressions
that matches this sentence is :
a) Рt ε r (Q(t))
b) ∀ t ε r (Q(t))
c) ¬ t ε r (Q(t))
d) ~ t ε r (Q(t))
View Answer
Answer: b
Explanation:∀
is used denote “for all” in SQL.
6. Which of the
following is the comparison operator in tuple relational calculus
a) ⇒
b) =
c) ε
d) All of the
mentioned
View Answer
Answer: b
Explanation: The comparison operators are (<, ≤, =, =,
>, ≥).
7. An expression in
the domain relational calculus is of the form
a) {P(x1, x2, . . . ,
xn) | < x1, x2, . . . , xn > }
b) {x1, x2, . . . ,
xn | < x1, x2, . . . , xn > }
c) { x1, x2, . . . ,
xn | x1, x2, . . . , xn}
d) {< x1, x2, . .
. , xn > | P(x1, x2, . . . , xn)}
View Answer
Answer: d
Explanation: Here x1, x2, . . . , xn represent domain
variables. P represents a formula composed of atoms, as was the case in the
tuple relational calculus.
8. Find the names of
all instructors in the Physics department together with the course id of all
courses they teach:
a) {< c > | Ð s
(< c, a, s, y, b, r, t >ε section
∧s = “Fall” ∧ y = “2009”
∨Ðu (< c, a, s, y, b, r, t >ε section
∧s = “Spring” ∧ y = “2010”
b) {< n, c > |
Рi, a (< i, c, a, s, y > ε teaches
∧ Ð d, s (< i, n, d, s > ε instructor ∧ d = “Physics”))}
c) {< n > | Ð
i, d, s (< i, n, d, s > ε instructor ∧
s > 80000)}
d) {< i, n, d, s
> | < i, n, d, s > ε instructor ∧
s > 80000}
View Answer
Answer: b
Explanation: None.
9. In domain
relaional calculus “there exist” can be expressed as
a) (P1(x))
b) (P1(x)) Ð x
c) V x (P1(x))
d) Ð x (P1(x))
View Answer
Answer: d
Explanation:Ð is used to denote “some” values in
relational calculus.
10. A set of possible
data values is called
a) Attribute
b) Degree
c) Tuple
d) Domain
View Answer
Answer: d
Explanation: None.
1. An ________ is a
set of entities of the same type that share the same properties, or attributes.
a) Entity set
b) Attribute set
c) Relation set
d) Entity model
View Answer
Answer: a
Explanation: An entity is a “thing” or “object” in the
real world that is distinguishable from all other objects.
2. Entity is a
_________
a) Object of relation
b) Present working
model
c) Thing in real
world
d) Model of relation
View Answer
Answer: c
Explanation: For example, each person in a university is
an entity.
3. The descriptive
property possessed by each entity set is _________
a) Entity
b) Attribute
c) Relation
d) Model
View Answer
Answer: b
Explanation: Possible attributes of the instructor entity
set are ID, name, dept name, and salary.
4. The function that
an entity plays in a relationship is called that entity’s _____________
a) Participation
b) Position
c) Role
d) Instance
View Answer
Answer: c
Explanation: A relationship is an association among
several entities.
5. The attribute name
could be structured as a attribute consisting of first name, middle initial, and
last name. This type of attribute is called
a) Simple attribute
b) Composite
attribute
c) Multivalued
attribute
d) Derived attribute
View Answer
Answer: b
Explanation: Composite attributes can be divided into
subparts (that is, other attributes).
6. The attribute AGE
is calculated from DATE_OF_BIRTH . The attribute AGE is
a) Single valued
b) Multi valued
c) Composite
d) Derived
View Answer
Answer: d
Explanation: The value for this type of attribute can be
derived from the values of other related attributes or entities.
7. Not applicable
condition can be represented in relation entry as
a) NA
b) 0
c) NULL
d) Blank Space
View Answer
Answer: c
Explanation: NULL always represents that the value is not
present.
8. Which of the
following can be a multivalued attribute ?
a) Phone_number
b) Name
c) Date_of_birth
d) All of the
mentioned
View Answer
Answer: a
Explanation: Name and Date_of_birth cannot hold more than
1 value.
9. Which of the
following is a single valued attribute
a) Register_number
b) Address
c) SUBJECT_TAKEN
d) Reference
View Answer
Answer: a
Explanation: None.
10. In a relation
between the entities the type and condition of the relation should be specified
. That is called as______attribute.
a) Desciptive
b) Derived
c) Recursive
d) Relative
View Answer
Answer: a
Explanation: Consider the entity sets student and
section, which participate in a relationship set takes. We may wish to store a
descriptive attribute grade with the relationship to record the grade that a
student got in the class.
1. _____________
express the number of entities to which another entity can be associated via a
relationship set.
a) Mapping
Cardinality
b) Relational
Cardinality
c) Participation
Constraints
d) None of the
mentioned
View Answer
Answer: a
Explanation: Mapping cardinality is also called as
cardinality ratio.
2. An entity in A is
associated with at most one entity in B, and an entity in B is associated with
at most one entity in A.This is called as
a) One-to-many
b) One-to-one
c) Many-to-many
d) Many-to-one
View Answer
Answer: b
Explanation: Here one entity in one set is related to one
one entity in other set.
3. An entity in A is
associated with at most one entity in B. An entity in B, however, can be
associated with any number (zero or more) of entities in A.
a) One-to-many
b) One-to-one
c) Many-to-many
d) Many-to-one
View Answer
Answer: d
Explanation: Here more than one entity in one set is
related to one one entity in other set.
4. Data integrity
constraints are used to:
a) Control who is
allowed access to the data
b) Ensure that
duplicate records are not entered into the table
c) Improve the
quality of data entered for a specific property
d) Prevent users from
changing the values stored in the table
View Answer
Answer: c
Explanation: The data entered will be in a particular
cell (i.e., table column).
5. Establishing
limits on allowable property values, and specifying a set of acceptable,
predefined options that can be assigned to a property are examples of:
a) Attributes
b) Data integrity
constraints
c) Method constraints
d) Referential
integrity constraints
View Answer
Answer: b
Explanation: Only particular value satsfying the
constraints are entered in column .
6. Which of the
following can be addressed by enforcing a referential integrity constraint?
a) All phone numbers
must include the area code
b) Certain fields are
required (such as the email address, or phone number) before the record is
accepted
c) Information on the
customer must be known before anything can be sold to that customer
d) Then entering an
order quantity, the user must input a number and not some text (i.e., 12 rather
than ‘a dozen’)
View Answer
Answer: c
Explanation: None.
7. ______ is a
special type of integrity constraint that relates two relations & maintains
consistency across the relations.
a) Entity Integrity
Constraints
b) Referential
Integrity Constraints
c) Domain Integrity
Constraints
d) Domain Constraints
View Answer
Answer: b
Explanation: None.
8. Which one of the
following uniquely identifies the elements in the relation?
a) Secondary Key
b) Primary key
c) Foreign key
d) Composite key
View Answer
Answer: b
Explanation: Primary key checks for not null and
uniqueness constraint .
9. Drop Table cannot
be used to drop a table referenced by a _________ constraint.
a) Local Key
b) Primary Key
c) Composite Key
d) Foreign Key
View Answer
Answer: d
Explanation: Foreign key is used when primary key of one
relation is used in another relation .
10. ____________ is
preferred method for enforcing data integrity
a) Constraints
b) Stored Procedure
c) Triggers
d) Cursors
View Answer
Answer: a
Explanation: Constraints are specified to restrict
entries in the relation.
1. Which of the
following gives a logical structure of the database graphically ?
a)
Entity-relationship diagram
b) Entity diagram
c) Database diagram
d) Architectural
representation
View Answer
Answer: a
Explanation: E-R diagrams are simple and clear—qualities
that may well account in large part for the widespread use of the E-R model.
2. The entity
relationship set is represented in E-R diagram as
a) Double diamonds
b) Undivided
rectangles
c) Dashed lines
d) Diamond
View Answer
Answer: d
Explanation: Dashed lines link attributes of a
relationship set to the relationship set.
3. The Rectangles
divided into two parts represents
a) Entity set
b) Relationship set
c) Attributes of a
relationship set
d) Primary key
View Answer
Answer: a
Explanation: The first part of the rectangle , contains
the name of the entity set. The second part contains the names of all the
attributes of the entity set.
4. Consider a
directed line(->) from the relationship set advisor to both entity sets
instructor and student. This indicates _________ cardinality
a) One to many
b) One to one
c) Many to many
d) Many to one
View Answer
Answer: b
Explanation: This indicates that an instructor may advise
at most one student, and a student may have at most one advisor.
5. We indicate roles
in E-R diagrams by labeling the lines that connect ___________ to __________
a) Diamond , diamond
b) Rectangle, diamond
c) Rectangle,
rectangle
d) Diamond, rectangle
View Answer
Answer: d
Explanation: Diamond represents a relationship set and
rectangle represents a entity set.
6. An entity set that
does not have sufficient attributes to form a primary key is termed a __________
a) Strong entity set
b) Variant set
c) Weak entity set
d) Variable set
View Answer
Answer: c
Explanation: An entity set that has a primary key is
termed a strong entity set.
7. For a weak entity
set to be meaningful, it must be associated with another entity set, called the
a) Identifying set
b) Owner set
c) Neighbour set
d) Strong entity set
View Answer
Answer: a
Explanation: Every weak entity must be associated with an
identifying entity; that is, the weak entity set is said to be existence
dependent on the identifying entity set. The identifying entity set is said to
own the weak entity set that it identifies.It is also called as owner entity
set.
8. Weak entity set is
represented as
a) Underline
b) Double line
c) Double diamond
d) Double rectangle
View Answer
Answer: c
Explanation: An entity set that has a primary key is
termed a strong entity set.
9. If you were
collecting and storing information about your music collection, an album would
be considered a(n) _____
a) Relation
b) Entity
c) Instance
d) Attribute
View Answer
Answer: b
Explanation: An entity set is a logical container for
instances of an entity type and instances of any type derived from that entity
type.
10. What term is used
to refer to a specific record in your music database; for instance; information
stored about a specific album?
a) Relation
b) Instance
c) Table
c) Column
View Answer
Answer: b
Explanation: The environment of database is said to be
instance. A database instance or an ‘instance’ is made up of the background
processes needed by the database
1. Which one of the
following can be treated as a primary key in teaches relation ?
a) Id
b) Semester
c) Sec_id
d) Year
View Answer
Answer: a
Explanation: Here Id is the only attribute that has to
have unique entry.
2. The primary key in
the section relation is
a) Course_id
b) Sec_id
c) Both Course_id and
Sec_id
d) All the attributes
View Answer
Answer: c
Explanation: Both the entries has unique entry.
3. Select * from
teaches where Sec_id = ‘CS-101’ ;
Which of the
following Id is selected for the following query ?
a) 1003
b) 1001
c) None
d) Error message
appears
View Answer
Answer: d
Explanation: The value CS-101 matches the Course_id but
not Id .
4. Select
Id,Course_id,Building from section s and teaches t where t.year=2009 ;
Which of the
following Id are displayed ?
a) 1003
b) 1001
c) Both 1003 and 1001
d) Error message
appears
View Answer
Answer: c
Explanation: Two rows are select in the above query.
5. The query which
selects the Course_id ‘CS-101’ from the section relation is
a) Select Course_id
from section where Building = ‘Richard’;
b) Select Course_id
from section where Year = ‘2009’;
c) Select Course_id
from teaches where Building = ‘Packyard’;
d) Select Course_id
from section where Sec_id = ‘3’;
View Answer
Answer: b
Explanation: The year ‘2009’ should be selected from the
section relation.
6.
CREATE TABLE SECTION
(Course_id VARCHAR
(8),
Sec_id VARCHAR (8),
Semester VARCHAR (6),
YEAR NUMERIC (4,0),
Building NUMERIC
(15),
PRIMARY KEY (course
id, sec id, semester, YEAR),
FOREIGN KEY (course
id) REFERENCES course);
Which of the
following has an error in the above create table for the relation section
a) Primary key
(course id, sec id, semester, year)
b) Foreign key
(course id) references course
c) Year numeric (4,0)
d) Building numeric
(15)
View Answer
Answer: d
Explanation: It should be replaced by Year Building varchar
(15).
7. The relation with
primary key can be created using
a) Create table
instructor ( Id , Name)
b) Create table
instructor ( Id , Name , primary key(name))
c) Create table
instructor ( Id , Name , primary key (Id))
d) Create table
instructor ( Id unique, Name )
View Answer
Answer: c
Explanation: The value Name cannot be a primary key.
8. How can the values
in the relation teaches be deleted ?
a) Drop table
teaches;
b) Delete from
teaches;
c) Purge table
teaches;
d) Delete from
teaches where Id =’Null’;
View Answer
Answer: b
Explanation: Delete table cleans the entry from the
table.
9. In the above
teaches relation ” Select * from teaches where Year = ‘2010’” displays how many
rows ?
a) 2
b) 4
c) 5
d) 1
View Answer
Answer: a
Explanation: There are two tuples with year is 2009.
10. The relation
changes can be got back using ________ command
a) Flashback
b) Purge
c) Delete
d) Getback
View Answer
Answer: a
Explanation: Purge deletes the table and delete cleans
the table entry.
1. Let us consider phone_number
,which can take single or several values . Treating phone_numberas an _________
permits instructors to have several phone numbers (including zero) associated
with them.
a) Entity
b) Attribute
c) Relation
d) Value
View Answer
Answer: a
Explanation: Treating a phone as an attribute
phone_number implies that instructors have precisely one phone number each.
2. The total
participation by entities is represented in E-R diagram as
a) Dashed line
b) Double line
c) Double rectangle
d) Circle
View Answer
Answer: b
Explanation: It is used to represent the relation between
several attributes.
3. Given the basic ER
and relational models, which of the following is INCORRECT?
a) An attribute of an
entity can have more than one value
b) An attribute of an
entity can be composite
c) In a row of a
relational table, an attribute can have more than one value
d) In a row of a
relational table, an attribute can have exactly one value or a NULL value
View Answer
Answer: c
Explanation: It is possible to have several values for a
single attribute provide it is a multi-valued attribute.
4. Which of the
following indicates the maximum number of entities that can be involved in a
relationship?
a) Minimum
cardinality
b) Maximum
cardinality
c) ERD
d) Greater Entity
Count
View Answer
Answer: b
Explanation: In SQL (Structured Query Language), the term
cardinality refers to the uniqueness of data values contained in a particular
column (attribute) of a database table.
5. In E-R diagram
generalization is represented by
a) Ellipse
b) Dashed ellipse
c) Rectangle
d) Triangle
View Answer
Answer: d
Explanation: Ellipse represents attributes,rectangle
represents entity.
6. What is a
relationship called when it is maintained between two entities?
a) Unary
b) Binary
c) Ternary
d) Quaternary
View Answer
Answer: b
Explanation: Binary word usually represents two
attributes.
7. Which of the
following is a low level operator?
a) Insert
b) Update
c) Delete
d) Directory
View Answer
Answer: d
Explanation: Directory is a low level to word on in file
system .
8. Key to represent
relationship between tables is called
a) Primary key
b) Secondary Key
c) Foreign Key
d) None of the
mentioned
View Answer
Answer: c
Explanation: Primary key of one relation used as an
attribute in another relation is called foreign key.
9. A window into a
portion of a database is
a) Schema
b) View
c) Query
d) Data dictionary
View Answer
Answer: b
Explanation: View is a logical portion of a database
which is needed by some users.
10. A primary key is
combined with a foreign key creates
a) Parent-Child
relation ship between the tables that connect them
b) Many to many
relationship between the tables that connect them
c) Network model
between the tables that connect them
d) None of the mentioned
View Answer
Answer: a
Explanation: Using the two relationships mother and
father provides us a record of a child’s mother, even if we are not aware of
the father’s identity; a null value would be required if the ternary
relationship parent is used. Using binary relationship sets is preferable in
this case
1. The entity set
person is classified as student and employee. This process is called _________
a) Generalization
b) Specialization
c) Inheritance
d) Constraint
generalization
View Answer
Answer: b
Explanation: The process of designating subgroupings
within an entity set is called specialization.
2. Which relationship
is used to represent a specialization entity ?
a) ISA
b) AIS
c) ONIS
d) WHOIS
View Answer
Answer: a
Explanation: In terms of an E-R diagram, specialization
is depicted by a hollow arrow-head pointing from the specialized entity to the
other entity.
3. The refinement
from an initial entity set into successive levels of entity subgroupings
represents a ________ design process in which distinctions are made explicit.
a) Hierarchy
b) Bottom-up
c) Top-down
d) Radical
View Answer
Answer: c
Explanation: The design process may also proceed in a
bottom-up manner, in which multiple entity sets are synthesized into a
higher-level entity set on the basis of common features.
4. There are
similarities between the instructor entity set and the secretary entity set in
the sense that they have several attributes that are conceptually the same
across the two entity sets: namely, the identifier, name, and salary
attributes. This process is called
a) Commonality
b) Specialization
c) Generalization
d) Similarity
View Answer
Answer: c
Explanation: Generalization is used to emphasize the
similarities among lower-level entity sets and to hide the differences.
5. If an entity set
is a lower-level entity set in more than one ISA relationship, then the entity
set has
a) Hierarchy
b) Multilevel
inheritance
c) Single inheritance
d) Multiple
inheritance
View Answer
Answer: d
Explanation: The attributes of the higher-level entity
sets are said to be inherited by the lower-level entity sets.
6. A _____________
constraint requires that an entity belong to no more than one lower-level
entity set.
a) Disjointness
b) Uniqueness
c) Special
d) Relational
View Answer
Answer: a
Explanation: For example, student entity can satisfy only
one condition for the student type attribute; an entity can be either a
graduate student or an undergraduate student, but cannot be both.
7. Consider the
employee work-team example, and assume that certain employees participate in
more than one work team . A given employee may therefore appear in more than
one of the team entity sets that are lower level entity sets of employee. Thus,
the generalization is _____________
a) Overlapping
b) Disjointness
c) Uniqueness
d) Relational
View Answer
Answer: a
Explanation: In overlapping generalizations, the same
entity may belong to more than one lower-level entity set within a single
generalization.
8. The completeness
constraint may be one of the following: Total generalization or specialization
, Partial generalization or specialization . Which is the default ?
a) Total
b) Partial
c) Should be
specified
d) Cannot be
determined
View Answer
Answer: b
Explanation: Partial generalization or specialization –
Some higher-level entities may not belong to any lower-level entity set.
9. Functional
dependencies are a generalization of
a) Key dependencies
b) Relation
dependencies
c) Database
dependencies
d) None of the mentioned
View Answer
Answer: a
Explanation: The subclasses are combined to form the
superclass.
10. Which of the
following is another name for weak entity?
a) Child
b) Owner
c) Dominant
d) All of the
mentioned
View Answer
Answer: a
Explanation: A parent may be called as a strong entity.
1. Which is the main
relation which is used in the university database which is referenced by all
other relation of the university.
a) Teaches
b) Course
c) Department
d) Section
View Answer
Answer: c
Explanation: Department is the only relation which forms
the main part of the university database .
2. The department
relation has the an entry budget whose type has to be replaced by
a) Varchar (20)
b) Varchar2 (20)
c) Numeric (12,2)
d) Numeric
View Answer
Answer: c
Explanation: Department is the only relation which forms
the main part of the university database.
3. In the course
relation the title field should throw an error in case of any missing title.
The command to be added in title is
a) Unique
b) Not null
c) 0
d) Null
View Answer
Answer: b
Explanation: By specifying not null the value cannot be
left blank.
4. In the above DDL
command the foreign key entries are got by using the keyword
a) References
b) Key reference
c) Relating
d) None of the
mentioned
View Answer
Answer: a
Explanation: References (table_name) give the prior table
name for the entry.
5. Identify the error
in the section relation
a) No error
b) Year numeric (4,0)
c) Building varchar
(15)
d) Sec_id varchar (8)
View Answer
Answer: a
Explanation: The building and the sec_id have varchar
values and year is of numeric type. So no such errors are found in the
relation.
6. The following
entry is given in to the instructor relation .
(100202,Drake,Biology,30000)
Identify the output
of the query given
a) Row(s) inserted
b) Error in ID of
insert
c) Error in Name of
insert
d) Error in Salary of
the insert
View Answer
Answer: b
Explanation: The varchar(5) value cannot hold the entry
100202.
7. Which of the
following can be used as a primary key entry of the instructor relation.
a) DEPT_NAME
b) NAME
c) ID
d) All of the
mentioned
View Answer
Answer: c
Explanation: The value ID can only be primary key unlike
dept_name which is used as a foreign key.
8. In the section
relation which of the following is used as a foreign key ?
a) Course_id
b) Course_id,sec_id
c) Room_number
d)
Course_id,sec_id,room_number
View Answer
Answer: a
Explanation: Course_id is the only field which is present
in the course relation.
9. In order to
include an attribute Name to the teaches relation which of the following
command is used ?
a) Alter table
teaches include Name;
b) Alter table
teaches add Name;
c) Alter table
teaches add Name varchar;
d) Alter table
teaches add Name varchar(20);
View Answer
Answer: d
Explanation: The form of the alter table command is
alter table r add AD;
where r is the name
of an existing relation, A is the name of the attribute to be added, and D is
the type of the added attribute.
10. To replace the
relation section with some other relation the initial step to be carried out is
a) Delete section;
b) Drop section;
c) Delete from
section;
d) Replace section
new_table ;
View Answer
Answer: b
Explanation: Droping the table drops all the references
to that table .
1. Which of the
following command is used to display the departments of the instructor relation
?
a) Select * from
instructor where Dept_name = Finance;
b) Select * from
instructor ;
c) Select dept_name
from instructor;
d) Select dept_name
for instructor where Name=Jackson;
View Answer
Answer: c
Explanation: Only one field is necessary for the query
and where clause is not needed for the selection.
2. How can we select
the elements which have common Dept_name in both the relation ?
a) Select * from
instructor i , course c where i.Dept_name=c.Dept_name;
b) Select Dept name
from instructor ,Course ;
c) Select * from
instructor i , course c ;
d) Select Dept_name
from instructor where Dept_name = NULL;
View Answer
Answer: a
Explanation: Here only the common elements are displayed
.
3. Select distinct Dept_name
from instructor ;
How many row(s) are
displayed ?
a) 4
b) 3
c) 5
d) Error
View Answer
Answer: a
Explanation: Distinct keyword eliminates the the common
Dept_name .
4. Suppose the
Authority want to include a new instructor for the title Neuroscience what
command should be inserted ?
a) Insert into
instructor values(12111,Emma,NeuroScience,200000);
b) Insert into course
values(12111,Introduction,NeuroScience,2);
c) Insert into
instructor values(12111,Emma,Biology,200000);
Insert into course
values(BIO-112,Introduction to Neuro Science,NeuroScience,2);
d) Insert into course
values(12111,Emma,NeuroScience,200000);
View Answer
Answer: c
Explanation: The values have to be inserted into both the
relations to be intact .
5. If a person all
the people in Music department gets fired which of the following has to be
performed on the instructor relation ?
a) Delete
Dept_name=Music in instructor;
b) Delete from
instructor where Dept_name=Music;
c) Remove Dept_name=
Music
d) All of the
mentioned
View Answer
Answer: b
Explanation: Delete from table_name where condition .
6.
SELECT DISTINCT
T.name
FROM instructor AS T,
instructor AS S
WHERE T.salary >
S.salary AND S.dept name = ’Comp.Sci.’;
What will be
displayed as the value of name for the above query ?
a) Hayley
b) Jackson
c) Hayley and Crick
d) Crick
View Answer
Answer: d
Explanation: Only the greatest salary in Comp.Sci dept is
selected for the query.
7.
SELECT Name
FROM instructor
WHERE salary >
SOME (SELECT salary FROM instructor WHERE dept_name = 'Comp.Sci.');
How many rows are
selected ?
a) 3
b) 4
c) 2
d) 1
View Answer
Answer: d
Explanation: This displays the names of instructors with
salary greater than that of some (at least one) instructor in the Biology
department .
8. How will you
select the Names whose first letter is E ?
a) SELECT Name
FROM instructor
WHERE Name LIKE ’A%;
b) SELECT Name
FROM course
WHERE Name LIKE ’A%;
c) SELECT Dept_name
FROM instructor
WHERE Name LIKE ’A%;
d) SELECT Name
FROM instructor
WHERE Dept_name LIKE ’A%;
View Answer
Answer: a
Explanation: % is used to indicate that some characters
may appear .
9. Which function is
used to find the count of distinct departments?
a) Dist
b) Distinct
c) Count
d) Count,Dist
View Answer
Answer: a
Explanation: Count (distinct ID) is the correct usage .
10. Which function is
used to identify the title with Least scope ?
a) Min(Credits)
b) Max(Credits)
c) Min(title)
d) Min(Salary)
View Answer
Answer: a
Explanation: Max is used to find the highest element and
Min is used to find the lowest element .
1. A domain is ______
if elements of the domain are considered to be indivisible units.
a) Atomic
b) Subatomic
c) Substructure
d) Subset
View Answer
Answer: a
Explanation: A set of names is an example of a nonatomic
value.
2. Identify the
composite attributes
a) Salary
b) Credits
c) Section_id
d) None of the
mentioned
View Answer
Answer: d
Explanation: Composite attributes, such as an attribute
address with component attributes street, city, state, and zip have nonatomic
domains.
3. Consider the
relation given below and ind the maximum normal form applicable to them
1. R(A, B) WITH
productions { A --> B }
2. R(A, B) WITH
productions { B --> A }
3 R(A, B) WITH
productions {A —> B, B --> A }
4 R(A, B, C) WITH productions {A -->B, B
--> A, AB --> C }
a) 1, 2 and 3 are in
3NF and 4 is in BCNF
b) 1 and 2 are in
BCNF and 3 and 4 are in 3NF
c) All are in 3NF
d) All are in BCNF
View Answer
Answer: d
Explanation: One of the more desirable normal forms that
we can obtain is Boyce–Codd normal form (BCNF). It eliminates all redundancy
that can be discovered based on functional dependencies.
4. Which one is based
on multi-valued dependency:
a) First
b) Second
c) Third
d) Fourth
View Answer
Answer: d
Explanation: One of the more desirable normal forms that
we can obtain is Boyce–Codd normal form (BCNF). It eliminates all redundancy
that can be discovered based on functional dependencies.
5. If a relation is
in BCNF, then it is also in
a) 1 NF
b) 2 NF
c) 3 NF
d) All of the
mentioned
View Answer
Answer: d
Explanation: Third normal form (3NF) relaxes this
constraint slightly by allowing certain nontrivial functionaldependencieswhose
left side is not a superkey.
6. If every non-key
attribute is functionally depedent primary key, then the relation will be in
a) First normal form
b) Second normal form
c) Third form
d) Fourth normal form
View Answer
Answer: b
Explanation: Third normal form (3NF) relaxes this
constraint slightly by allowing certain nontrivial functionaldependencieswhose
left side is not a superkey.
7. If an attribute of
a composite key is dependent on an attribute of the other composite key, a
normalization called _____ is needed.
a) DKNF
b) BCNF
c) Fourth
d) Third
View Answer
Answer: b
Explanation: BCNF eliminates all redundancy that can be
discovered based on functional dependencies.
8. The term for
information that describes what type of data is available in a database is:
a) Data dictionary
b) data repository
c) Index data
d) Metadata
View Answer
Answer: d
Explanation: Meta data is generally data about a data.
9. A data type that
creates unique numbers for key columns in Microsoft Access is:
a) Autonumber
b) Boolean
c) Sequential key
d) Sequential number
View Answer
Answer: a
Explanation: This can be taken as a primary key .
10. A dependency
exist between two columns when
a) Together they
constitute a composite key for the table
b) Knowing the value
in one column determines the value stored in another column
c) The table is in
3NF
d) Together they
constitute a foreign key
View Answer
Answer: a
Explanation: Given a set F of functional dependencies on
a schema, we can prove that certain other functional dependencies also hold on
the schema.
1. In the __________
normal form, a composite attribute is converted to individual attributes.
A) First
B) Second
C) Third
D) Fourth
View Answer
Answer: a
Explanation: The first normal form is used to eliminate
the duplicate information.
2. A table on the
many side of a one to many or many 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
View Answer
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.
3. 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
View Answer
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.
4. Which-one ofthe
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
View Answer
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).
5. Functional
Dependencies are the types of constraints that are based on______
a) Key
b) Key revisited
c) Superset key
d) None of the
mentioned
View Answer
Answer: a
Explanation: Key is the basic element needed for the
constraints.
6. 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
View Answer
Answer: c
Explanation: Normalisation is the process of removing
redundancy and unwanted data.
7. 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
View Answer
Answer: c
Explanation: The first normal form is used to eliminate
the duplicate information.
8. Which forms has a
relation that possesses data about an individual entity:
a) 2NF
b) 3NF
c) 4NF
d) 5NF
View Answer
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.
9. Which forms are based
on the concept of functional dependency:
a) 1NF
b) 2NF
c) 3NF
d) 4NF
View Answer
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.
10. 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
View Answer
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. We can use the
following three rules to find logically implied functional dependencies. This
collection of rules is called
a) Axioms
b) Armstrong’s axioms
c) Armstrong
d) Closure
View Answer
Answer: b
Explanation: By applying these rules repeatedly, we can
find all of F+, given F.
2. Which of the
following is not a Armstrong’s Axiom ?
a) Reflexivity rule
b) Transitivity rule
c) Pseudotransitivity
rule
d) Augmentation rule
View Answer
Answer: c
Explanation: It is possible to use Armstrong’s axioms to
prove that Pseudotransitivity rule is sound.
3. The relation
employee(ID,name,street,Credit,street,city,salary) is decomposed into
employee1 (ID, name)
employee2 (name,
street, city, salary)
This type of decomposition
is called
a) Lossless
decomposition
b) Lossless-join
decomposition
c) Both a and b
d) None of the
mentioned
View Answer
Answer: d
Explanation: Lossy-join decomposition is the
decomposition used here .
4. Inst_dept (ID,
name, salary, dept name, building, budget) is decomposed into
instructor (ID, name,
dept name, salary)
department (dept
name, building, budget)
This comes under
a) Lossy-join
decomposition
b) Lossy
decomposition
c) Lossless-join
decomposition
d) Both a and b
View Answer
Answer: d
Explanation: Lossy-join decomposition is the
decomposition used here .
5. There are two
functional dependencies with the same set of attributes on the left side of the
arrow:
A->BC
A->B
This can be combined
as
a) A->BC
b) A->B
c) B->C
d) None of the mentioned
View Answer
Answer: a
Explanation: This can be computed as the canonical cover
.
6. Consider a
relation R(A,B,C,D,E) with the following functional dependencies:
ABC -> DE and
D -> AB
The number of
superkeys of R is:
a) 2
b) 7
c) 10
d) 12
View Answer
Answer: c
Explanation: A superkey is a combination of columns that
uniquely identifies any row within a relational database management system
(RDBMS) table.
7. Suppose we wish to
find the ID’s of the employees that are managed by people who are managed by
the employee with ID 123. Here are two possible queries:
I.SELECT ee.empID
FROM Emps ee, Emps ff
WHERE ee.mgrID = ff.empID AND ff.mgrID = 123;
II.SELECT empID
FROM Emps
WHERE mgrID IN
(SELECT empID FROM Emps WHERE mgrID = 123);
Which, if any, of the
two queries above will correctly (in SQL2) get the desired set of employee
ID’s?
a) Both I and II
b) I only
c) II only
d) Neither I nor I
View Answer
Answer: a
Explanation: The query can be satisfied by any of the two
options.
8. Suppose relation R(A,B)
currently has tuples {(1,2), (1,3), (3,4)} and relation S(B,C) currently has
{(2,5), (4,6), (7,8)}. Then the number of tuples in the result of the SQL
query:
<i>SELECT *
FROM R NATURAL OUTER JOIN S;
</i>IS:
a) 2
b) 4
c) 6
d) None of the
mentioned
View Answer
Answer: a
Explanation: The SQL NATURAL JOIN is a type of EQUI JOIN
and is structured in such a way that, columns with same name of associate
tables will appear once only.
9. Suppose now that
R(A,B) and S(A,B) are two relations with r and s tuples, respectively (again,
not necessarily distinct). If m is the number of (not necessarily distinct)
tuples in the result of the SQL query:
R intersect S;
Then which of the
following is the most restrictive, correct condition on the value of m?
(a) m = min(r,s)
(b) 0 <= m <= r + s
(c) min(r,s) <= m <= max(r,s)
(d) 0 <= m <= min(r,s)
View Answer
Answer: d
Explanation: The value of m must lie between the min
value of r and s and 0.
10. Suppose relation
R(A,B,C,D,E) has the following functional dependencies:
A -> B
B -> C
BC -> A
A -> D
E -> A
D -> E
Which of the
following is not a key?
a) A
b) E
c) B,C
d) D
View Answer
Answer: c
Explanation: Here the keys are not formed by B and C.
1. A relation is in
____________ if an attribute of a composite key is dependent on an attribute of
other composite key.
a) 2NF
b) 3NF
c) BCNF
d) 1NF
View Answer
Answer: b
Explanation: A relation is in 3 NF if an attribute of a
composite key is dependent on an attribute of other composite key. (If an
attribute of a composite key is dependent on an attribute of other composite
key then the relation is not in BCNF, hence it has to be decomposed.).
2. What are the
desirable properties of a decomposition
a) Partition
constraint
b) Dependency
preservation
c) Redundancy
d) Security
View Answer
Answer: b
Explanation: Lossless join and dependency preserving are
the two goals of the decomposition.
3. R (A,B,C,D) is a
relation. Which of the following does not have a lossless join dependency
preserving BCNF decomposition.
a) A->_B, B->_CD
b) A->B, B->C,
C->D
c) AB->C, C->AD
d) A->BCD
View Answer
Answer: d
Explanation: This relation gives a relation without any
loss in the values.
Class (course id,
title, dept name, credits, sec id, semester, YEAR, building, room NUMBER,
capacity, TIME slot id)
The SET OF functional
dependencies that we require TO hold ON class are:
course id->title,
dept name, credits
building, room
number->capacity
course id, sec id,
semester, year->building, room NUMBER, TIME slot id
A candidate KEY FOR
this schema IS {course id, sec id, semester, YEAR}
4. Consider the above
conditions. Which of the following relation holds ?
a) Course id->
title, dept name, credits
b) Title-> dept
name, credits
c) Dept name->
credits
d) Cannot be
determined
View Answer
Answer: a
Explanation: Here course id is not a superkey. Thus,
class is not in BCNF.
5. The algorithm that
takes a set of dependencies and adds one schema at a time, instead of
decomposing the initial schema repeatedly is
a) BCNF algorithm
b) 2NF algorithm
c) 3NF synthesis
algorithm
d) 1NF algorithm
View Answer
Answer: c
Explanation: The result is not uniquely defined, since a
set of functional dependencies can have more than one canonical cover, and,
further, in some cases, the result of the algorithm depends on the order in
which it considers the dependencies in Fc .
6. The functional
dependency can be tested easily on the materialized view, using the constraints
____________.
a) Primary key
b) Null
c) Unique
d) Both Null and
Unique
View Answer
Answer: d
Explanation: Primary key contains both unique and not
null constraints .
7. Which normal form
is considered adequate for normal relational database design?
a) 2NF
b) 5NF
c) 4NF
d) 3NF
View Answer
Answer: d
Explanation: A relational database table is often
described as “normalized” if it is in the Third Normal Form because most of the
3NF tables are free of insertion, update, and deletion anomalies .
8. Relation R with an
associated set of functional dependencies, F, is decomposed into BCNF. The
redundancy (arising out of functional dependencies) in the resulting set of
relations is
a) Zero
b) More than zero but
less than that of an equivalent 3NF decomposition
c) Proportional to
the size of F+
d) Indeterminate
View Answer
Answer: b
Explanation: Redundancy in BCNF is low when compared to
3NF. For more details on BCNF .
9. A table has fields
F1, F2, F3, F4, and F5, with the following functional dependencies:
F1->F3
F2->F4
(F1,F2)->F5
in terms of
normalization, this table is in
a) 1NF
b) 2NF
c) 3NF
d) None of the
mentioned
View Answer
Answer: a
Explanation: Since the primary key is not given we have
to derive the primary key of the table. Using the closure set of attributes we
get the primary key as (F1,F2). From functional dependencies, “F1->F3,
F2->F4”, we can see that there is partial functional dependency therefore it
is not in 1NF. Hence the table is in 1NF.
10. Let
R(A,B,C,D,E,P,G) be a relational schema in which the following FDs are known to
hold:
AB->CD
DE->P
C->E
P->C
B->G
The relation schema R
is
a) in BCNF
b) in 3NF, but not in
BCNF
c) in 2NF, but not in
3NF
d) not in 2NF
View Answer
Answer: d
Explanation: From the closure set of attributes we can
see that the key for the relation is AB. The FD B->G is a partial
dependency, hence it is not in 2NF.
1. The normal form
which satisfies multivalued dependencies and which is in BCNF is
a) 4 NF
b) 3 NF
c) 2 NF
d) All of the
mentioned
View Answer
Answer: a
Explanation: Fourth normal form is more restrictive than
BCNF.
2. Which of the
following is a tuple-generating dependencies ?
a) Functional
dependency
b)
Equality-generating dependencies
c) Multivalued
dependencies
d) Non-functional
dependency
View Answer
Answer: c
Explanation: Multivalued dependencies, do not rule out
the existence of certain tuples. Instead, they require that other tuples of a
certain form be present in the relation.
3. The main task
carried out in the __________ is to remove repeating attributes to separate tables.
a) First Normal Form
b) Second Normal Form
c) Third Normal Form
d) Fourth Normal Form
View Answer
Answer: a
Explanation: Multivalued dependencies, do not rule out
the existence of certain tuples. Instead, they require that other tuples of a
certain form be present in the relation.
4. Which of the
normal form is based on multivalued dependencies ?
a) First
b) Second
c) Third
d) Fourth
View Answer
Answer: d
Explanation: Multivalued dependencies, do not rule out
the existence of certain tuples. Instead, they require that other tuples of a
certain form be present in the relation.
5. Which forms has a
relation that possesses data about an individual entity?
a) 2NF
b) 3NF
c) 4NF
d) 5NF
View Answer
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.
6. If a multivalued
dependency holds and is not implied by the corresponding functional dependency,
it usually arises from one of the following sources.
a) A many-to-many
relationship set
b) A multivalued
attribute of an entity set
c) A one-to-many
relationship set
d) Both A
many-to-many relationship set and A multivalued attribute of an entity set
View Answer
Answer: d
Explanation: For a many-to-many relationship set each
related entity set has its own schema and there is an additional schema for the
relationship set. For a multivalued attribute, a separate schema is created
consisting of that attribute and the primary key of the entity set.
7. Which of the
following has each related entity set has its own schema and there is an
additional schema for the relationship set?
a) A many-to-many
relationship set
b) A multivalued
attribute of an entity set
c) A one-to-many
relationship set
d) None of the
mentioned
View Answer
Answer: a
Explanation: If a multivalued dependency holds and is not
implied by the corresponding functional dependency, it usually arises from this
source.
8. In which of the
following , a separate schema is created consisting of that attribute and the
primary key of the entity set.
a) A many-to-many
relationship set
b) A multivalued
attribute of an entity set
c) A one-to-many
relationship set
d) None of the
mentioned
View Answer
Answer: b
Explanation: If a multivalued dependency holds and is not
implied by the corresponding functional dependency, it usually arises from this
source.
9. Fifth Normal form
is concerned with
a) Functional
dependency
b) Multivalued
dependency
c) Join dependency
d) Domain-key
View Answer
Answer: c
Explanation: If a multivalued dependency holds and is not
implied by the corresponding functional dependency, it usually arises from this
source.
10. In 2NF
a) No functional dependencies
(FDs) exist
b) No multivalued
dependencies (MVDs) exist
c) No partial FDs
exist
d) No partial MVDs
exist
View Answer
Answer: c
Explanation: If a multivalued dependency holds and is not
implied by the corresponding functional dependency, it usually arises from this
source.
1. _____________ can
help us detect poor E-R design.
a) Database Design
Process
b) E-R Design Process
c) Relational scheme
d) Functional
dependencies
View Answer
Answer: d
Explanation: For eg.,Suppose an instructor entity set had
attributes dept name and dept address, and there is a functional dependency
dept name -> dept address.
2. If a multivalued
dependency holds and is not implied by the corresponding functional dependency,
it usually arises from one of the following sources.
a) A many-to-many
relationship set
b) A multivalued
attribute of an entity set
c) A one-to-many
relationship set
d) Both A
many-to-many relationship set and A multivalued attribute of an entity set
View Answer
Answer: d
Explanation: For a many-to-many relationship set each
related entity set has its own schema and there is an additional schema for the
relationship set. For a multivalued attribute, a separate schema is created
consisting of that attribute and the primary key of the entity set.
3. Which of the
following has each related entity set has its own schema and there is an
additional schema for the relationship set.
a) A many-to-many
relationship set
b) A multivalued
attribute of an entity set
c) A one-to-many
relationship set
d) All of the
mentioned
View Answer
Answer: a
Explanation: If a multivalued dependency holds and is not
implied by the corresponding functional dependency, it usually arises from this
source.
4. In which of the
following , a separate schema is created consisting of that attribute and the
primary key of the entity set.
a) A many-to-many
relationship set
b) A multivalued
attribute of an entity set
c) A one-to-many
relationship set
d) All of the
mentioned
View Answer
Answer: b
Explanation: If a multivalued dependency holds and is not
implied by the corresponding functional dependency, it usually arises from this
source.
5. Suppose the user
finds the usage of room number and phone number in a relational schema there is
confusion.This is reduced by
a) Unique-role
assumption
b) Unique-key
assignment
c) Role intergral
assignment
d) None of the
mentioned
View Answer
Answer: a
Explanation: A desirable feature of a database design is
the unique-role assumption, which means that each attribute name has a unique
meaning in the database.
6. What is the best
way to represent the attributes in a large database?
a) Relational-and
b) Concatenation
c) Dot representation
d) All of the
mentioned
View Answer
Answer: b
Explanation: Example inst sec and student sec.
7. Designers use
which of the following to tune performance of systems to support time-critical
operations?
a) Denormalization
b) Redundant
optimization
c) Optimization
d) Realization
View Answer
Answer: a
Explanation: The process of taking a normalized schema
and making it nonnormalized is called denormalization.
8. In the schema
(dept name, size) we have relations total inst 2007, total inst 2008 . Which
dependency have lead to this relation ?
a) Dept name,
year->size
b) Year->size
c) Dept name->size
d) Size->year
View Answer
Answer: a
Explanation: The process of taking a normalized schema
and making it nonnormalized is called denormalization.
9. Relation dept
year(dept name, total inst 2007, total inst 2008, total inst 2009) .Here the
only functional dependencies are from dept name to the other attributes .This
relation is in
a) Fourth NF
b) BCNF
c) Third NF
d) Second NF
View Answer
Answer: b
Explanation: BCNF has only one normal form.
10. Thus a _______ of
course data gives the values of all attributes, such as title and department,
of all courses at a particular point in time.
a) Instance
b) Snapshot
c) Both Instance and
Snapshot
d) All of the
mentioned
View Answer
Answer: b
Explanation: We use the term snapshot of data to mean the
value of the data at a particular point in time.
11. Representations
such as the in the dept year relation, with one column for each value of an
attribute, are called _______ they are widely used in spreadsheets and reports
and in data analysis tools.
a) Cross-tabs
b) Snapshot
c) Both Cross-tabs
and Snapshot
d) All of the
mentioned
View Answer
Answer: a
Explanation: SQL includes features to convert data from a
normal relational representation to a crosstab.
1. An approach to
website design with the emphasis on converting visitors to outcomes required by
the owner is referred to as:
a) Web usability
b) Persuasion
c) Web accessibility
d) None of the
mentioned
View Answer
Answer: b
Explanation: In computing, graphical user interface is a
type of user interface that allows users to interact with electronic devices.
2. A method of
modelling and describing user tasks for an interactive application is referred
to as:
a) Customer journey
b) Primary persona
c) Use case
d) Web design persona
View Answer
Answer: c
Explanation: The actions in GUI are usually performed
through direct manipulation of the graphical elements.
3. Information
architecture influences:
a) Answer choice
b) Site structure
c) Labeling
d) Navigation design
View Answer
Answer: b
Explanation: The actions in GUI are usually performed
through direct manipulation of the graphical elements.
4. Also known as
schematics, a way of illustrating the layout of an individual webpage is a:
a) Wireframe
b) Sitemap
c) Card sorting
d) Blueprint
View Answer
Answer: a
Explanation: An application programming interface
specifies how some software components should interact with each other.
5. A graphical or
text depiction of the relationship between different groups of content on a
website is referred to as a:
a) Wireframe
b) Blueprint
c) Sitemap
d) Card sorting
View Answer
Answer: c
Explanation: An application programming interface
specifies how some software components should interact with each other.
6. Blueprints are
intended to:
a) Prototype of the
screen layout showing navigation and main design elements
b) Show the grouping
of pages and user journeys
c) Indicate the
structure of a site during site design and as a user feature
d) Prototype typical
customer journeys or clickstreams through a website
View Answer
Answer: c
Explanation: A blueprint is a reproduction of a technical
drawing, documenting an architecture or an engineering design, using a contact
print process .
7. Storyboards are
intended to:
a) Indicate the
structure of a site during site design and as a user feature
b) Prototype of the
screen layout showing navigation and main design elements
c) Integrate
consistently available components on the webpage (e.g. navigation, search
boxes)
d) Prototype typical customer
journeys or click streams through a website
View Answer
Answer: d
Explanation: An application programming interface
specifies how some software components should interact with each other.
8. Which of the
following occupies boot record of hard and floppy disks and activated during
computer startup?
a) Worm
b) Boot sector virus
c) Macro virus
d) Virus
View Answer
Answer: b
Explanation: A blueprint is a reproduction of a technical
drawing, documenting an architecture or an engineering design, using a contact
print process .
9. A graphical or
text depiction of the relationship between different groups of content on a
website is a:
a) Page template
b) Wireframe
c) Site map
d) Cascading style
sheet (CSS)
View Answer
Answer: c
Explanation: In computing, graphical user interface is a
type of user interface that allows users to interact with electronic devices.
10. Which of the
following is a description of information organization schemes?
a) Minimising the
number of clicks needed to access relevant content
b) Providing an
overall design to a site consistent with the positioning of the products and
services
c) The menu options
chosen to group and categorize information
d) Providing specific
content and services appropriate to different audience members
View Answer
Answer: c
Explanation: In computing, graphical user interface is a
type of user interface that allows users to interact with electronic devices.
1. Which of the
following is a valid uniform resource locator ?
c) www.ann.in
View Answer
Answer: a
Explanation: A uniform resource locator (URL) is a
globally unique name for each document that can be accessed on the Web.
2. http://www.google.com/search?q=silberschatz
In the above URL
which one is the argument which is used for processing of the URL?
a) google
b) google.com
c) search
d) q=silberschatz
View Answer
Answer: d
Explanation: Argument is always placed after ? symbol.
3. HTTP defines two
ways in which values entered by a user at the browser can be sent to the Web
server. The _____ method encodes the values as part of the URL.
a) Post
b) Get
c) Read
d) Argument
View Answer
Answer: b
Explanation: For example, if the Google search page used
a form with an input parameter
named q with the get
method, and the user typed in the string “silberschatz” and submitted the form,
the browser would request the following URL from the Web server: http://www.google.com/search?q=silberschatz.
4. A __________ is a
program running on the server machine,which accepts requests from a Web browser
and sends back results in the form of HTML documents.
a) HTML
b) HTTP
c) Web Server
d) Web browser
View Answer
Answer: c
Explanation: The browser and Web server communicate via
HTTP. Web servers provide powerful features, beyond the simple transfer of
documents.
5. The application program
typically communicates with a database server, through ___________ or other
protocols, in order to get or store data.
a) JDBC
b) ODBC
c) All of the
mentioned
d) None of the
mentioned
View Answer
Answer: c
Explanation: The common gateway interface (CGI) standard
defines how the Web server communicates with application programs.
6. This extra
information is usually maintained in the form of a _________ at the client.
a) Cookie
b) History
c) Remainder
d) None of the
mentioned
View Answer
Answer: a
Explanation: A cookie is simply a small piece of text
containing identifying information and with an associated name.
7. Which of the
following is not true about HTML ?
a)
<meta>…</meta>
b) <meta…./>
c)
<metadata>…</metadata>
d) <metadata
name=”” />
View Answer
Answer: b
Explanation: Meta data is the data about data which is
included in the meta data tag.
8. Html code
contains:
a) Tags
b) Attributes
c) Elements
d) All of the
mentioned
View Answer
Answer: d
Explanation:<> are tags,size is a attribute.
9. Html document must
always be saved with:
a) .html
b) .htm
c) .doc
d) Both .html &
.htm
View Answer
Answer: d
Explanation: .doc is used only for the word document
format.
10. How many levels
of headings are in html:
a) 2
b) 7
c) 6
d) 4
View Answer
Answer: c
Explanation: The heading levels are h1,h2,h3,h4,h5,h6.
1. The Java
__________ specification defines an application programming interface for
communication between the Web server and the application program.
a) Servlet
b) Server
c) Program
d) Randomize
View Answer
Answer: a
Explanation: Servlets are commonly used to generate
dynamic responses to HTTP requests.
2. The doGet() method
in the example extracts values of the parameter’s type and number by using
__________
a)
request.getParameter()
b) request.setParameter()
c)
responce.getParameter()
d)
responce.getAttribute()
View Answer
Answer: a
Explanation: These methods uses these values to run a
query against a database.
3. How many JDBC
driver types does Sun define?
a) One
b) Two
c) Three
d) Four
View Answer
Answer: d
Explanation: JBDB.DriverManager.getConnection() is used
to get the connection to the database.
4. Which JDBC driver
Type(s) can be used in either applet or servlet code?
a) Both Type 1 and
Type 2
b) Both Type 1 and
Type 3
c) Both Type 3 and
Type 4
d) Type 4 only
View Answer
Answer: c
Explanation: In a Type 3 driver, a three-tier approach is
used to accessing databases. The JDBC clients use standard network sockets to
communicate with an middleware application server.In a Type 4 driver, a pure
Java-based driver that communicates directly with vendor’s database through
socket connection.
5. What MySQL
property is used to create a surrogate key in MySQL?
a) UNIQUE
b) SEQUENCE
c) AUTO_INCREMENT
d) None of the
mentioned
View Answer
Answer: c
Explanation: A surrogate key in a database is a unique
identifier for either an entity in the modeled world or an object in the
database.
6. A JSP is
transformed into a(n):
a) Java applet
b) Java servlet
c) Either 1 or 2
above
d) Neither 1 nor 2
above
View Answer
Answer: b
Explanation: Servlets are commonly used to generate
dynamic responses to HTTP requests.
7. Which JDBC driver
Type(s) is(are) the JDBC-ODBC bridge?
a) Type 1
b) Type 2
c) Type 3
d) Type 4
View Answer
Answer: a
Explanation: In a Type 1 driver, a JDBC bridge is used to
access ODBC drivers installed on each client machine.
8. What programming
language(s) or scripting language(s) does Java Server Pages (JSP) support?
a) VBScript only
b) Jscript only
c) Java only
d) All of the mentioned
View Answer
Answer: c
Explanation: JSP primarily uses Java for the certain
codes.
9. What is bytecode?
a) Machine-specific
code
b) Java code
c)
Machine-independent code
d) None of the
mentioned
View Answer
Answer: c
Explanation: Java bytecode is the form of instructions
that the Java virtual machine executes. Each bytecode opcode is one byte in
length, although some require parameters, resulting in some multi-byte
instructions.
10. Where is metadata
stored in MySQL?
a) In the MySQL
database metadata
b) In the MySQL
database metasql
c) In the MySQL
database mysql
d) None of the
mentioned
View Answer
Answer: c
Explanation: Metadata contains data about other data
which is given in the … tags.
1. Which of the
following is true for Seeheim model?
a) Presentation is
abstracted from dialogue and Application
b) Presentation and
Dialogue is abstracted from Application
c) Presentation and
Application is abstracted from Dialogue
d) None of the
mentioned
View Answer
Answer: a
Explanation: Presentation is abstracted from dialogue and
application.
2. Which of the unit
operation is used in Model view controller?
a) Is a Decomposition
b) Part Whole
Decomposition
c) All of the
mentioned
d) None of the
mentioned
View Answer
Answer: b
Explanation: Part whole decomposition is applied to MVC.
3. Memory address
refers to the successive memory words and the machine is called as
_______________
a) word addressable
b) byte addressable
c) bit addressable
d) Terra byte
addressable
View Answer
Answer: a
Explanation: Part whole decomposition is applied to MVC.
4. Which layer deals
which deals with user interaction is called _____________ layer.
a) Business logic
b) Presentation
c) User interaction
d) Data access
View Answer
Answer: b
Explanation: The single application may have several
different versions of this layer, corresponding to distinct kinds of interfaces
such as Web browsers, and user interfaces of mobile phones, which have much
smaller screens.
5. The _____________
layer, which provides a high-level view of data and actions on data.
a) Business logic
b) Presentation
c) User interaction
d) Data access
View Answer
Answer: a
Explanation: The single application may have several
different versions of this layer, corresponding to distinct kinds of interfaces
such as Web browsers, and user interfaces of mobile phones, which have much
smaller screens.
6. The ______________
layer, which provides the interface between the business-logic layer and the
underlying database.
a) Business logic
b) Presentation
c) User interaction
d) Data access
View Answer
Answer: d
Explanation: Many applications use an object-oriented
language to code the business-logic layer, and use an object-oriented model of
data, while the underlying database is a relational database.
7. The _____________
system is widely used for mapping from Java objects to relations.
a) Hibernate
b) Object oriented
c) Objective
d) None of the
mentioned
View Answer
Answer: a
Explanation: In Hibernate, the mapping from each Java
class to one or more relations is specified in a mapping file.
8. Which among the
following are the functions that any system with a user interface must provide?
a) Presentation
b) Dialogue
c) All of the
mentioned
d) None of the
mentioned
View Answer
Answer: a
Explanation: Presentation and Application are the
functions that any system with a user interface must provide.
9. Which of the
following is the main task accomplished by the user?
a) Compose a document
b) Create a spread
sheet
c) Send mail
d) All of the
mentioned
View Answer
Answer: d
Explanation: All of the mentioned are the main task
accomplished by the user.
10. What are the
portability concerns founded in Seeheim model?
a) Replacing the
presentation toolkit
b) Replacing the
application toolkit
c) Replacing the dialogue
toolkit
d) Replacing the
presentation & application toolkit
View Answer
Answer: d
Explanation: The portability concerns founded in Seeheim
model are- Replacing the presentation toolkit and Replacing the application
toolkit.
1. Which schema
object instructs Oracle to connect to a remotely access an object of a
database?
a) Sequence
b) Remote link
c) Database link
d) Data link
View Answer
Answer: d
Explanation: A database link (DBlink) is a definition of
how to establish a connection from one Oracle database to another.
2. DML changes are
a) Insert
b) Update
c) Create
d) Both Insert and
Update
View Answer
Answer: d
Explanation: Create is a DDL operation.
3. Which of the
following object types below cannot be replicated?
a) Data
b) Trigger
c) View
d) Sequence
View Answer
Answer: d
Explanation: Sequence is a series of items which is like
a unique index .
4. How to force a log
switch?
a) By using ALTER
SYSTEM LOG
b) By using ALTER
SYSTEM SWITCH LOGFILE
c) By using ALTER
SYSTEM SWITCH LOGS
d) By using ALTER SYS
LOGFILES
View Answer
Answer: b
Explanation: ALTER SYSTEM ARCHIVE LOG CURRENT is the best
practice for production backup scripts with RMAN. .
5. In the following
query, which expression is evaluated first?
SELECT id_number,
(quantity - 100 / 0.15 - 35 * 20) FROM inventory
a) 100 / 0.15
b) quantity – 100
c) 35*20
d) 0.15-35
View Answer
Answer: a
Explanation: According to the precedence of expression as
in BODMAS the expression evaluated.
6. The ORDER BY
clause can only be used in
a) SELECT queries
b) INSERT queries
c) GROUP BY queries
d) HAVING queries
View Answer
Answer: a
Explanation: SELECT column_name,column_name
FROM table_name
ORDER BY
column_name,column_name ASC|DESC;.
7. Which of the
following rule below are categories of index?
a) Column and
Functional
b) Multiple Column
and functional
c) Column, Multiple
Column and functional
d) None of the
mentioned
View Answer
Answer: a
Explanation: The CREATE INDEX statement is used to create
indexes in tables.
8. What is the
purpose of SMON background process?
a) Performs crash
recovery when a failed instance starts up again
b) Performs recovery
when a user process fails
c) Writes redo log
entries to disk
d) None of the
mentioned
View Answer
Answer: a
Explanation: SMON (System MONitor) is an Oracle
background process created when you start a database instance .
9. Which of the
following queries are legal?
a) SELECT deptno,
count(deptno) FROM emp GROUP BY ename;
b) SELECT deptno,
count(deptno), job FROM emp GROUP BY deptno;
c) SELECT deptno,
avg(sal) FROM emp;
d) SELECT deptno,
avg(sal) FROM emp GROUP BY deptno;
View Answer
Answer: d
Explanation: For aggregate functions group by clause is
necessary.
10. Which of the
following queries displays the sum of all employee salaries for those employees
not making commission, for each job, including only those sums greater than
2500?
a) select job,
sum(sal) from emp where sum(sal) > 2500 and comm is null;
b) select job,
sum(sal) from emp where comm is null group by job having sum(sal) > 2500;
c) select job,
sum(sal) from emp where sum(sal) > 2500 and comm is null group by job;
d) select job,
sum(sal) from emp group by job having sum(sal) > 2500 and comm is not null;
View Answer
Answer: b
Explanation: For aggregate functions group by clause is
necessary.
1. The indirect
change of the values of a variable in one module by another module is called
a) Internal change
b) Inter-module
change
c) Side effect
d) Side-module update
View Answer
Answer: c
Explanation: The module of the search tree and the flow
is directed by its values.
2. Which of the
following data structure is not linear data structure?
a) Arrays
b) Linked lists
c) Arrays &
Linked lists
d) None of the
mentioned
View Answer
Answer: d
Explanation: Both array and linked lists are in data
structure concepts.
3. Which of the
following data structure is linear data structure?
a) Trees
b) Graphs
c) Arrays
d) None of the
mentioned
View Answer
Answer: c
Explanation: Tree and graphs are not linear.
4. Which of the
following criterion is NOT written using the proper syntax?
a) “Haris”
b) <500
c) NO VALUE
d) Between #1/1/2000#
and #12/31/2000#
View Answer
Answer: c
Explanation: NO VALUE cannot be specified.
5. The operation of
processing each element in the list is known as
a) Sorting
b) Merging
c) Inserting
d) Traversal
View Answer
Answer: d
Explanation: There are several types of traversals.
6. Finding the
location of the element with a given value is:
a) Traversal
b) Search
c) Sort
d) None of the mentioned
View Answer
Answer: b
Explanation: Search is performed by traversing through
the tree.
7. Arrays are best
data structures
a) For relatively
permanent collections of data
b) For the size of
the structure and the data in the structure are constantly changing
c) All of the
mentioned
d) None of the
mentioned
View Answer
Answer: a
Explanation: The operator tree has a tree like format
where the evaluation starts from root of the tree.
8. Linked lists are
best suited
a) For relatively
permanent collections of data
b) For the size of
the structure and the data in the structure are constantly changing
c) All of the
mentioned
d) None of the
mentioned
View Answer
Answer: b
Explanation: A linked list is a data structure consisting
of a group of nodes which together represent a sequence.
9. Each array
declaration need not give, implicitly or explicitly, the information about
a) The name of array
b) The data type of
array
c) The first data
from the set to be stored
d) The index set of
the array
View Answer
Answer: c
Explanation: The operator tree has a tree like format
where the evaluation starts from root of the tree.
10. The elements of
an array are stored successively in memory cells because
a) By this way
computer can keep track only the address of the first element and the addresses
of other elements can be calculated
b) The architecture
of computer memory does not allow arrays to store other than serially
c) All of the
mentioned
d) None of the
mentioned
View Answer
Answer: a
Explanation: Memory is always allotted in order.
1. In
_________________ attacks, the attacker manages to get an application to
execute an SQL query created by the attacker.
a) SQL injection
b) SQL
c) Direct
d) Application
View Answer
Answer: a
Explanation: Application security has to deal with
several security threats and issues beyond those handled by SQL authorization .
2. A Web site that
allows users to enter text, such as a comment or a name, and then stores it and
later displays it to other users, is potentially vulnerable to a kind of attack
called a ___________________ attack.
a) Two-factor
authentication
b) Cross-site request
forgery
c) Cross-site
scripting
d) Cross-site scoring
scripting
View Answer
Answer: c
Explanation: In such an attack, a malicious user enters
code written in a client-side scripting language such as JavaScript or Flash
instead of entering a valid name or comment.
3. _________ is an
attack which forces an end user to execute unwanted actions on a web
application in which he/she is currently authenticated.
a) Two-factor
authentication
b) Cross-site request
forgery
c) Cross-site
scripting
d) Cross-site scoring
scripting
View Answer
Answer: b
Explanation: Cross-site request forgery, also known as a
one-click attack or session riding and abbreviated as CSRF or XSRF.
4. Many applications
use _________________, where two independent factors are used to identify a
user.
a) Two-factor
authentication
b) Cross-site request
forgery
c) Cross-site
scripting
d) Cross-site scoring
scripting
View Answer
Answer: a
Explanation: The two factors should not share a common
vulnerability.
5. Even with
two-factor authentication, users may still be vulnerable
to_____________attacks.
a) Radiant
b) Cross attack
c) scripting
d) Man-in-the-middle
View Answer
Answer: d
Explanation: In such attacks, a user attempting to
connect to the application is diverted to a fake Web site, which accepts the
password from the user, and uses it immediately to authenticate to the original
application.
6. A single
______________ further allows the user to be authenticated once, and multiple
applications can then verify the user’s identity through an authentication
service without requiring reauthentication.
a) OpenID
b) Sign-on system
c) Security Assertion
Markup Language (SAML)
d) Virtual Private
Database (VPD)
View Answer
Answer: b
Explanation: Once the user logged in at one site, he does
not have to enter his user name and password at other sites that use the same
single sign-on service.
7. The
___________________ is a standard for exchanging authentication and
authorization information between different security domains, to provide
cross-organization single sign-on.
a) OpenID
b) Sign-on system
c) Security Assertion
Markup Language (SAML)
d) Virtual Private
Database (VPD)
View Answer
Answer: c
Explanation: The user’s password and other authentication
factors are never revealed to the application, and the user need not register
explicitly with the application.
8. The __________
standard is an alternative for single sign-on across organizations, and has
seen increasing acceptance in recent years.
a) OpenID
b) Single-site system
c) Security Assertion
Markup Language (SAML)
d) Virtual Private
Database (VPD)
View Answer
Answer: a
Explanation: The user’s password and other authentication
factors are never revealed to the application, and the user need not register
explicitly with the application.
9. _______________
allows a system administrator to associate a function with a relation; the
function returns a predicate that must be added to any query that uses the
relation.
a) OpenID
b) Single-site system
c) Security Assertion
Markup Language (SAML)
d) Virtual Private
Database (VPD)
View Answer
Answer: d
Explanation: Some database systems provide mechanisms for
fine-grained authorization.
10. VPD provides
authorization at the level of specific tuples, or rows, of a relation, and is
therefore said to be a _____________ mechanism.
a) Row-level
authorization
b) Column-level authentication
c) Row-type
authentication
d) Authorization
security
View Answer
Answer: a
Explanation: Oracle Virtual Private Database (VPD) allows
a system administrator to associate a function with a relation.
1. ___________ is
widely used today for protecting data in transit in a variety of applications
such as data transfer on the Internet, and on cellular phone networks.
a) Encryption
b) Data mining
c) Internet Security
d) Architectural
security
View Answer
Answer: a
Explanation: Encryption is also used to carry out other
tasks, such as authentication.
2. In a database
where the encryption is applied the data is cannot be handled by the
unauthorised user without
a) Encryption key
b) Decryption key
c) Primary key
d) Authorised key
View Answer
Answer: b
Explanation: Even if the message is intercepted by an
enemy, the enemy, not knowing the key, will not be able to decrypt and
understand the message.
3. Which of the
following is not a property of good encryption technique ?
a) Relatively simple
for authorized users to encrypt and decrypt data
b) Decryption key is
extremely difficult for an intruder to determine
c) Encryption depends
on a parameter of the algorithm called the encryption key
d) None of the
mentioned
View Answer
Answer: d
Explanation: Here a,b and c are the properties have to be
present in a good design of a encryption technique.
4. In which of the
following encryption key is used to encrypt and decrypt the data ?
a) Public key
b) Private key
c) Symmetric key
d) Asymmetric key
View Answer
Answer: c
Explanation: In public-key (also known as asymmetric-key)
encryption techniques, there are two different keys, the public key and the
private key, used to encrypt and decrypt the data.
5. Encryption of
small values, such as identifiers or names, is made complicated by the
possibility of __________
a) Dictionary attacks
b) Database attacks
c) Minor attacks
d) Random attacks
View Answer
Answer: a
Explanation: This happens when particularly if the
encryption key is publicly available.
6. Which one of the
following uses a 128bit round key to encrypt the data using XOR and use it in
reverse to decrypt it ?
a) Round key
algorithm
b) Public key
algorithm
c) Advanced
Encryption Standard
d) Asymmetric key
algorithm
View Answer
Answer: c
Explanation: The standard is based on the Rijndael
algorithm.
7. Which of the
following requires no password travel across the internet ?
a) Readable system
b) Manipulation
system
c) Challenge–response
system
d) Responce system
View Answer
Answer: c
Explanation: The database system sends a challenge string
to the user. The user encrypts the challenge string using a secret password as
encryption key and then returns the result. The database system can verify the
authenticity of the user by decrypting the string with the same secret password
and checking the result with the original challenge string.
8. Assymmetric
Encryption: Why can a message encrypted with the Public Key only be decrypted
with the receiver’s appropriate Private Key?
a) Not true, the
message can also be decrypted with the Public Key
b) A so called “one
way function with back door” is applyed for the encryption
c) The Public Key
contains a special function which is used to encrypt the message and which can
only be reversed by the appropriate Private Key
d) The encrypted
message contains the function for decryption which identifies the Private Key
View Answer
Answer: b
Explanation: An one-way function is a function which a
computer can calculate quickly, but whose reversal would last months or years.
An one-way function with back door can be reversed with the help of a couple of
additional information (the back door), but scarcely without this information.
The information for the back door is contained in the private Key.
9. Which is the
largest disadvantage of the symmetric Encryption?
a) More complex and
therefore more time-consuming calculations
b) Problem of the
secure transmission of the Secret Key
c) Less secure
encryption function
d) Isn’t used any
more
View Answer
Answer: b
Explanation: As there is only one key in the symmetrical
encryption, this must be known by both sender and recipient and this key is
sufficent to decrypt the secret message. Therefore it must be exchanged between
sender and receiver in such a manner that an unauthorized person can in no case
take possesion of it.
10. Which is the
principle of the encryption using a key?
a) The key indicates
which funcion is used for encryption. Thereby it is more difficult to decrypt a
intercepted message as the function is unknown
b) The key contains
the secret function for encryption including parameters. Only a password can
activate the key
c) All functions are
public, only the key is secret. It contains the parameters used for the
encryption resp. decryption
d) The key prevents
the user of having to reinstall the software at each change in technology or in
the functions for encryption
View Answer
Answer: b
Explanation: The encoding of a message is calculated by
an algorithm. If always the same algorithm would be used, it would be easy to
crack intercepted messages. However, it isn’t possible to invent a new
algorithm whenever the old one was cracked, therefor the possibility to
parameterize algorithms is needed and this is the assignment of the key.
1. Which of the
following is a physical storage media ?
a) Tape Storage
b) Optical Storage
c) Flash memory
d) All of the
mentioned
View Answer
Answer: d
Explanation: The storage media are classified by the
speed with which data can be accessed, by the cost per unit of data to buy the
medium, and by the medium’s reliability.
2. The _________ is
the fastest and most costly form of storage, which is relatively small; its use
is managed by the computer system hardware.
a) Cache
b) Disk
c) Main memory
d) Flash memory
View Answer
Answer: a
Explanation: Cache storage is easy to access because it
is closer to the processor.
3. Which of the
following stores several gigabytes of data but usually lost when power failure?
a) Flash memory
b) Disk
c) Main memory
d) Secondary memory
View Answer
Answer: c
Explanation: The contents of main memory are usually lost
if a power failure or system crash occurs.
4. The flash memory
storage used are
a) NOR Flash
b) OR Flash
c) AND Flash
d) All of the
mentioned
View Answer
Answer: a
Explanation: NAND flash has a much higher storage
capacity for a given cost, and is widely used for data storage in devices such
as cameras, music players, and cell phones.
5. __________ is
increasingly being used in server systems to improve performance by caching frequently
used data, since it provides faster access than disk, with larger storage
capacity than main memory.
a) Flash memory
b) Disk
c) Main memory
d) Secondary memory
View Answer
Answer: a
Explanation: Flash memory is of two types – NAND and NOR.
6. Which is the
cheapest memory device in terms of costs/bit ?
a) Semiconductor
memory
b) Magnetic disks
c) Compact disks
d) Magnetic tapes
View Answer
Answer: c
Explanation: Compact disk is used for easy storage at
lower cost .
7. The primary medium
for the long-term online storage of data is the __________ where the entire
database is stored on magnetic disk.
a) Semiconductor
memory
b) Magnetic disks
c) Compact disks
d) Magnetic tapes
View Answer
Answer: b
Explanation: The system must move the data from disk to
main memory so that they can be accessed .
8. Optical disk
_______ systems contain a few drives and numerous disks that can be loaded into
one of the drives automatically (by a robot arm) on demand.
a) Tape Storage
b) Jukebox
c) Flash memory
d) All of the
mentioned
View Answer
Answer: b
Explanation: The most popular form of optical disks are
CD and DVD.
9. There are
“record-once” versions of compact disk and digital video disk, which can be
written only once; such disks are also called __________ disks.
a) Write-once,
read-many (WORM)
b) CD-R
c) DVD-W
d) CD-ROM
View Answer
Answer: a
Explanation: There are also “multiple-write” versions of
compact disk (called CD-RW) and digital video disk (DVD-RW, DVD+RW, and DVD-RAM),
which can be written multiple times.
10. Tape storage is
referred to as __________ storage.
a) Direct-access
b) Random-access
c) Sequential-access
d) All of the
mentioned
View Answer
Answer: c
Explanation: Tape storage is used primarily for backup
and archival data.
1. In magnetic disk
________ stores information on a sector magnetically as reversals of the
direction of magnetization of the magnetic material.
a) Read–write head
b) Read-assemble head
c) Head–disk
assemblies
d) Disk arm
View Answer
Answer: d
Explanation: Each side of a platter of a disk has a
read–write head that moves across the platter to access different tracks.
2. A __________ is
the smallest unit of information that can be read from or written to the disk.
a) Track
b) Spindle
c) Sector
d) Platter
View Answer
Answer: c
Explanation: The disk surface is logically divided into
tracks, which are subdivided into sectors.
3. The disk platters
mounted on a spindle and the heads mounted on a disk arm are together known as
___________
a) Read-disk
assemblies
b) Head–disk
assemblies
c) Head-write
assemblies
d) Read-read
assemblies
View Answer
Answer: b
Explanation: Each side of a platter of a disk has a
read–write head that moves across the platter to access different tracks.
4. The disk
controller uses ________ at each sector to ensure that the data is not
corrupted on data retrieval.
a) Checksum
b) Unit drive
c) Read disk
d) Readsum
View Answer
Answer: a
Explanation: A disk controller interfaces between the
computer system and the actual hardware of the disk drive.
5. _________ is the
time from when a read or write request is issued to when data transfer begins.
a) Access time
b) Average seek time
c) Seek time
d) Rotational latency
time
View Answer
Answer: a
Explanation: To access (that is, to read or write) data
on a given sector of a disk, the arm first must move so that it is positioned
over the correct track, and then must wait for the sector to appear under it as
the disk rotates.
6. The time for
repositioning the arm is called the ________ and it increases with the distance
that the arm must move.
a) Access time
b) Average seek time
c) Seek time
d) Rotational latency
time
View Answer
Answer: c
Explanation: Typical seek times range from 2 to 30
milliseconds, depending on how far the track is from the initial arm position.
7. _________ is
around one-half of the maximum seek time.
a) Access time
b) Average seek time
c) Seek time
d) Rotational latency
time
View Answer
Answer: b
Explanation: Average seek times currently range between 4
and 10 milliseconds, depending on the disk model.
8. Once the head has
reached the desired track, the time spent waiting for the sector to be accessed
to appear under the head is called the _______________
a) Access time
b) Average seek time
c) Seek time
d) Rotational latency
time
View Answer
Answer: d
Explanation: Rotational speeds of disks today range from
5400 rotations per minute (90 rotations per second) up to 15,000 rotations per
minute (250 rotations per second), or, equivalently, 4 milliseconds to 11.1
milliseconds per rotation.
9. In Flash memory,
the erase operation can be performed on a number of pages, called an _______ at
once, and takes about 1 to 2 milliseconds.
a) Delete block
b) Erase block
c) Flash block
d) Read block
View Answer
Answer: b
Explanation: The size of an erase block (often referred
to as just “block” in flash literature) is usually significantly larger than
the block size of the storage system.
10. Hybrid disk
drives are hard-disk systems that combine magnetic storage with a smaller
amount of flash memory, which is used as a cache for frequently accessed data.
a) Hybrid drivers
b) Disk drivers
c) Hybrid disk
drivers
d) All of the
mentioned
View Answer
Answer: b
Explanation: Frequently accessed data that are rarely
updated are ideal for caching in flash memory.
1. Which level of
RAID refers to disk mirroring with block striping?
a) RAID level 1
b) RAID level 2
c) RAID level 0
d) RAID level 3
View Answer
Answer: a
Explanation: RAID level 1 refers to disk mirroring with
block striping.
2. Optical disk
technology uses
a) Helical scanning
b) DAT
c) A laser beam
d) RAID
View Answer
Answer: d
Explanation: Redundant Array of Inexpensive Disks.
3. With multiple
disks, we can improve the transfer rate as well by ___________ data across
multiple disks.
a) Striping
b) Dividing
c) Mirroring
d) Dividing
View Answer
Answer: a
Explanation: Data striping consists of splitting the bits
of each byte across multiple disks; such striping is called bitlevel striping.
4. Which one of the
following is a Stripping technique ?
a) Byte level
stripping
b) Raid level
stripping
c) Disk level
stripping
d) Block level
stripping
View Answer
Answer: d
Explanation: Block-level striping stripes blocks across
multiple disks. It treats the array of disks as a single large disk, and it
gives blocks logical numbers.
5. The RAID level
which mirroring is done along with stripping is
a) RAID 1+0
b) RAID 0
c) RAID 2
d) Both RAID 1+0 and
RAID 0
View Answer
Answer: d
Explanation: Mirroring without striping can also be used
with arrays of disks, to give the appearance of a single large, reliable disk.
6. Where performance
and reliability are both important, RAID level ____ is used.
a) 0
b) 1
c) 2
d) 0+1
View Answer
Answer: d
Explanation: Mirroring without striping can also be used
with arrays of disks, to give the appearance of a single large, reliable disk.
7. ______________
partitiones data and parity among all N+1 disks, instead of storing data in
N-disks and parity in one disk.
a) Block interleaved
parity
b) Block interleaved
distributed parity
c) Bit parity
d) Bit interleaved
parity
View Answer
Answer: b
Explanation: In level 5, all disks can participate in
satisfying read requests, unlike RAID level 4, where the parity disk cannot
participate, so level 5 increases the total number of requests that can be met
in a given amount of time.
8. Hardware RAID
implementations permit _________ that is, faulty disks can be removed and
replaced by new ones without turning power off.
a) Scrapping
b) Swapping
c) Hot swapping
d) None of the
mentioned
View Answer
Answer: c
Explanation: Hot
swapping reduces the
mean time to repair, since replacement of a disk does not have to wait until a
time when the system can be shut down.
9. ___________ is
popular for applications such as storage of log files in a database system,
since it offers the best write performance.
a) RAID level 1
b) RAID level 2
c) RAID level 0
d) RAID level 3
View Answer
Answer: a
Explanation: RAID level 1 refers to disk mirroring with
block striping.
10. ______________
which increases the number of I/O operations needed to write a single logical
block, pays a significant time penalty in terms of write performance.
a) RAID level 1
b) RAID level 2
c) RAID level 5
d) RAID level 3
View Answer
Answer: a
Explanation: In level 5, all disks can participate in
satisfying read requests, unlike RAID level 4, where the parity disk cannot
participate, so level 5 increases the total number of requests that can be met
in a given amount of time.
1. Tertiary storage
is built with :
a) a lot of money
b) unremovable media
c) removable media
d) secondary storage
View Answer
Answer: c
Explanation: Tertiary storage involves a robotic
mechanism which will mount (insert) and dismount removable mass storage media
into a storage device according to the system’s demands; this data is often
copied to secondary storage before use.
2. Operating system
is responsible for
a) disk
initialization
b) booting from disk
c) bad-bock recovery
d) all of the
mentioned
View Answer
Answer: d
Explanation: Tertiary storage involves a robotic
mechanism which will mount (insert) and dismount removable mass storage media
into a storage device according to the system’s demands; this data is often
copied to secondary storage before use.
3. A typical tape
drive is ________ a typical disk drive.
a) more expensive
than
b) cheaper than
c) of the same cost
as
d) none of the
mentioned
View Answer
Answer: a
Explanation: Tertiary storage involves a robotic
mechanism which will mount (insert) and dismount removable mass storage media
into a storage device according to the system’s demands; this data is often
copied to secondary storage before use.
4. During recovery
from a failure
a) each pair of
physical block is examined
b) specified pair of
physical block is examined
c) first pair of
physical block is examined
d) none of the
mentioned
View Answer
Answer: a
Explanation: Tertiary storage involves a robotic
mechanism which will mount (insert) and dismount removable mass storage media
into a storage device according to the system’s demands; this data is often
copied to secondary storage before use.
5. A magneto-optic
disk is :
a) primary storage
b) secondary storage
c) tertiary storage
d) removable disk
View Answer
Answer: c and d
Explanation: Tertiary storage involves a robotic
mechanism which will mount (insert) and dismount removable mass storage media
into a storage device according to the system’s demands; this data is often
copied to secondary storage before use.
6. Which of the
following is the process of selecting the data storage and data access
characteristics of the database?
a) Logical database
design
b) Physical database
design
c) Testing and
performance tuning
d) Evaluation and
selecting
View Answer
Answer: b
Explanation: Physical database design is the process of
selecting the data storage and data access characteristics of the database.
7. The replacement of
a bad block generally is not totally automatic because
a) data in bad block
can not be replaced
b) data in bad block
is usually lost
c) bad block does not
contain any data
d) none of the
mentioned
View Answer
Answer: b
Explanation: Physical database design is the process of
selecting the data storage and data access characteristics of the database.
8. Which of the
following is the oldest database model?
a) Relational
b) Hierarchical
c) Physical
d) Network
View Answer
Answer: d
Explanation: Network model has data stored in a
hierarchical network flow .
9. The surface area
of a tape is ________ the surface area of a disk.
a) much lesser than
b) much larger than
c) equal to
d) none of the
mentioned
View Answer
Answer: b
Explanation: Network model has data stored in a
hierarchical network flow .
10. Which one of the
following is not a secondary storage?
a) magnetic disks
b) magnetic tapes
c) ram
d) none of the
mentioned
View Answer
Answer: c
Explanation: Tertiary storage involves a robotic
mechanism which will mount (insert) and dismount removable mass storage media
into a storage device according to the system’s demands; this data is often
copied to secondary storage before use.
1. Which level of
RAID refers to disk mirroring with block striping?
a) RAID level 1
b) RAID level 2
c) RAID level 0
d) RAID level 3
View Answer
Answer: a
Explanation: RAID (redundant array of independent disks)
is a way of storing the same data in different places (thus, redundantly) on
multiple hard disks.
2. A unit of storage
that can store one or more records in a hash file organization is denoted as
a) Buckets
b) Disk pages
c) Blocks
d) Nodes
View Answer
Answer: a
Explanation: A unit of storage that can store one or more
records in a hash file organization is denoted as buckets.
3. The file
organization which allows us to read records that would satisfy the join
condition by using one block read is
a) Heap file
organization
b) Sequential file
organization
c) Clustering file organization
d) Hash file
organization
View Answer
Answer: c
Explanation: All systems in the cluster share a common
file structure via NFS, but not all disks are mounted on all other systems.
4. What are the
correct features of a distributed database?
a) Is always
connected to the internet
b) Always requires
more than three machines
c) Users see the data
in one global schema.
d) Have to specify
the physical location of the data when an update is done
View Answer
Answer: c
Explanation: Users see the data in one global schema.
5. Each tablespace in
an Oracle database consists of one or more files called
a) Files
b) name space
c) datafiles
d) PFILE
View Answer
Answer: c
Explanation: A data file is a computer file which stores
data to use by a computer application or system.
6. The management
information system (MIS) structure with one main computer
system is called a
a) Hierarchical MIS
structure
b) Distributed MIS
structure
c) Centralized MIS
structure
d) Decentralized MIS
structure
View Answer
Answer: c
Explanation: Structure of MIS may be understood by
looking at the physical components of the information system in an
organization.
7. A top-to-bottom
relationship among the items in a database is established by a
a) Hierarchical
schema
b) Network schema
c) Relational schema
d) All of the
mentioned
View Answer
Answer: a
Explanation: A hierarchical database model is a data
model in which the data is organized into a tree-like structure. The structure
allows representing information using parent/child relationships.
8. Choose the RDBMS
which supports full fledged client server application development
a) dBase V
b) Oracle 7.1
c) FoxPro 2.1
d) Ingress
View Answer
Answer: b
Explanation: RDBMS is Relational DataBase Management
System.
9. One approach to
standardization storing of data?
a) MIS
b) Structured
programming
c) CODASYL
specification
d) None of the
mentioned
View Answer
Answer: c
Explanation: CODASYL is an acronym for “Conference on
Data Systems Languages”.
10. The highest level
in the hierarchy of data organization is called
a) Data bank
b) Data base
c) Data file
d) Data record
View Answer
Answer: b
Explanation: Database is a collection of all tables which
contains the data in form of fields.
1. If a piece of data
is stored in two places in the database, then
a) Storage space is
wasted
b) Changing the data
in one spot will cause data inconsistency
c) In can be more
easily accessed
d) Storage space is
wasted & Changing the data in one spot will cause data inconsistency
View Answer
Answer: d
Explanation: The database is always consistent and so
there is no duplication .
2. An audit trail
___________
a) Is used to make
backup copies
b) Is the recorded
history of operations performed on a file
c) Can be used to
restore lost information
d) None of the mentioned
View Answer
Answer: b
Explanation: This is more useful for all recovery actions
.
3. Large collection
of files are called ____________
a) Fields
b) Records
c) Database
d) Sectors
View Answer
Answer: c
Explanation: The operator tree has a tree like format
where the evaluation starts from root of the tree .
4. Which of the
following hardware component is the most important to the operation of database
management system?
a) High resolution
video display
b) Printer
c) High speed, large
capacity disk
d) Mouse
View Answer
Answer: c
Explanation: All the data are stored in form of memory in
the disk.
5. Which of the
following is not true of the traditional approach to information processing
a) There is common
sharing of data among the various applications
b) It is file
oriented
c) Programs are
dependent on the file
d) It is inflexible
View Answer
Answer: a
Explanation: All the data are stored in form of memory in
the disk.
6. Which of these is
not a feature of Hierarchical model?
a) Organizes the data
in tree-like structure
b) Parent node can
have any number of child nodes
c) Root node does not
have any parent
d) Child node can
have any number of parent nodes
View Answer
Answer: d
Explanation: The data are traversed using several
algorithms.
7. Which of these
data models is an extension of relational data model?
a) Object-oriented
data model
b) Object-relational
data model
c) Semi structured
data model
d) None of the
mentioned
View Answer
Answer: b
Explanation: All the data are stored in form of memory in
the disk.
8. The information
about data in a database is called _______
a) Metadata
b) Hyper data
c) Tera data
d) None of the
mentioned
View Answer
Answer: a
Explanation: Metadata is information about a data.
9. A data dictionary
is a special file that contains?
a) The names of all
fields in all files
b) The data types of
all fields in all files
c) The widths of all
fields in all files
d) All of the
mentioned
View Answer
Answer: d
Explanation: The data dictionary is structured in tables
and views, just like other database data.
10. The DBMS acts as
an interface between what two components of an enterprise-class database
system?
a) Database
application and the database
b) Data and the
database
c) The user and the
database application
d) Database
application and SQL
View Answer
Answer: a
Explanation: Database application is the interface with
the user to access the database
1. A relational
database system needs to maintain data about the relations, such as the schema
of the relations. This is called
a) Metadata
b) Catalog
c) Log
d) Dictionary
View Answer
Answer: a
Explanation: Each side of a platter of a disk has a
read–write head that moves across the platter to access different tracks.
2. Relational schemas
and other metadata about relations are stored in a structure called the
____________
a) Metadata
b) Catalog
c) Log
d) Data Dictionary
View Answer
Answer: d
Explanation: Data dictionary is also called as system
catalog.
3. ___________ is the
collection of memory structures and Oracle background processes that operates
against an Oracle database.
a) Database
b) Instance
c) Tablespace
d) Segment
View Answer
Answer: b
Explanation: Instance is a snapshot of database at any
point of time.
4. A ________ is a
logical grouping of database objects, usually to facilitate security,
performance, or the availability of database objects such as tables and
indexes.
a) Tablespace
b) Segments
c) Extents
d) Blocks
View Answer
Answer: a
Explanation: A tablespace is a storage location where the
actual data underlying database objects can be kept.
5. A tablespace is
further broken down into ________
a) Tablespace
b) Segments
c) Extents
d) Blocks
View Answer
Answer: b
Explanation: Segment names are used in create table and
create index commands to place tables or indexes on specific database devices.
6. __________ is a
contiguous group of blocks allocated for use as part of a table, index, and so
forth.
a) Tablespace
b) Segment
c) Extent
d) Block
View Answer
Answer: c
Explanation: An extent is a set of contiguous blocks
allocated in a database.
7. ________ is the
smallest unit of allocation in an Oracle database.
a) Database
b) Instance
c) Tablespace
d) Database Block
View Answer
Answer: d
Explanation: Data block is a form of database space
allocation.
8. An Oracle
__________ is a set of tables and views that are used as a read-only reference
about the database.
a) Database
dictionary
b) Dictionary table
c) Data dictionary
d) Dictionary
View Answer
Answer: c
Explanation: Data dictionary is also called as system
catalog.
9. A data dictionary
is created when a __________ created.
a) Instance
b) Segment
c) Database
d) Dictionary
View Answer
Answer: c
Explanation: Data dictionary is also called as system
catalog.
10. An Oracle object type
has two parts the _________ and__________
a) Instance and body
b) Segment and blocks
c) Specification and
body
d) Body and segment
View Answer
Answer: c
Explanation: Segment names are used in create table and
create index commands to place tables or indexes on specific database devices.
An extent is a set of contiguous blocks allocated in a database.
1. The _______ is
that part of main memory available for storage of copies of disk blocks.
a) Buffer
b) Catalog
c) Storage
d) Secondary storage
View Answer
Answer: a
Explanation: There is always a copy kept on disk of every
block, but the copy on disk may be a version of the block older than the
version in the buffer.
2. A major goal of
the database system is to minimize the number of block transfers between the
disk and memory. This is achieved by
a) Buffer
b) Catalog
c) Storage
d) Secondary storage
View Answer
Answer: a
Explanation: There is always a copy kept on disk of every
block, but the copy on disk may be a version of the block older than the
version in the buffer.
3. The subsystem
responsible for the allocation of buffer space is called the ___________
a) Buffer
b) Buffer manager
c) Storage
d) Secondary storage
View Answer
Answer: b
Explanation: Programs in a database system make requests
(that is, calls) on the buffer manager when they need a block from disk.
4. In the buffer
where there is no space for another block, the bllock can be inserted using
a) Pinned block
strategy
b) Forced output
block
c) Buffer replacement
strategy
d) All of the
mentioned
View Answer
Answer: c
Explanation: Most operating systems use a least recently
used (LRU) scheme, in which the block that was referenced least recently is
written back to disk and is removed from the buffer.
5. A block that is
not allowed to be written back to disk is said to be ______________
a) Pinned
b) Forced
c) Buffer
d) All of the
mentioned
View Answer
Answer: a
Explanation: Although many operating systems do not
support pinned blocks, such a feature is essential for a database system that
is resilient to crashes.
6. There are
situations in which it is necessary to write back the block to disk, even
though the buffer space that it occupies is not needed. This write is called
the
a) Pinned block
strategy
b) Forced output
block
c) Buffer replacement
strategy
d) All of the
mentioned
View Answer
Answer: b
Explanation: The main-memory contents and thus buffer
contents are lost in a crash, whereas data on disk usually survive a crash.
7. The frequently
used buffer replacement strategy is
a) Most recently used
b) Least recently
used
c) Longest block
d) All of the
mentioned
View Answer
Answer: b
Explanation: If a block must be replaced, the least
recently referenced block is replaced.
8. In case the buffer
manager do not write the blocks properly then the buffer manager uses
a) Replacement
strategy
b) Forced strategy
c) Crash recovery
system
d) Both Replacement
and Forced strategy
View Answer
Answer: c
Explanation: The crash-recovery subsystem imposes
stringent constraints on block replacement.
9. The technique
where the blocks which have been used are replaced is called
a) Replacement
strategy
b) Forced strategy
c) Crash recovery
system
d) Most recently used
View Answer
Answer: d
Explanation: The optimal strategy for block replacement
is the most recently used (MRU) strategy.
10.
___________________ frees the space occupied by a block as soon as the final
tuple of that block has been processed.
a) Replacement
strategy
b) Forced strategy
c) Toss immediate
strategy
d) Most recently used
View Answer
Answer: c
Explanation: The optimal strategy for block replacement
is the most recently used (MRU) strategy.
1. In ordered indices
the file containing the records is sequentially ordered, a ___________ is an
index whose search key also defines the sequential order of the file.
a) Clustered index
b) Structured index
c) Unstructured index
d) Nonclustered index
View Answer
Answer: a
Explanation: Clustering index are also called primary
indices; the term primary index may appear to denote an index on a primary key,
but such indices can in fact be built on any search key.
2. Indices whose
search key specifies an order different from the sequential order of the file
are called ___________ indices.
a) Nonclustered
b) Secondary
c) All of the
mentioned
d) None of the
mentioned
View Answer
Answer: c
Explanation: Nonclustering index are also called
secondary indices.
3. An ____________
consists of a search-key value and pointers to one or more records with that
value as their search-key value.
a) Index entry
b) Index hash
c) Index cluster
d) Index map
View Answer
Answer: a
Explanation: The pointer to a record consists of the
identifier of a disk block and an offset within the disk block to identify the
record within the block.
4. In a _______
clustering index, the index record contains the search-key value and a pointer
to the first data record with that search-key value and the rest of the records
will be in the sequential pointers.
a) Dense
b) Sparse
c) Straight
d) Continuous
View Answer
Answer: a
Explanation: In a dense nonclustering index, the index
must store a list of pointers to all records with the same search-key value.
5. In a __________
index, an index entry appears for only some of the search-key values.
a) Dense
b) Sparse
c) Straight
d) Continuous
View Answer
Answer: a
Explanation: Sparse indices can be used only if the
relation is stored in sorted order of the search key, that is, if the index is
a clustering index.
6. Incase the indices
values are larger, index is created for these values of index. This is called
a) Pointed index
b) Sequential index
c) Multilevel index
d) Multiple index
View Answer
Answer: c
Explanation: Indices with two or more levels are called
multilevel indices.
7. A search key
containing more than one attribute is referred to as a _________ search key.
a) Simple
b) Composite
c) Compound
d) Secondary
View Answer
Answer: b
Explanation: The structure of the index is the same as
that of any other index, the only difference being that the search key is not a
single attribute, but rather is a list of attributes.
8. In B+ tree the
node which points to another node is called
a) Leaf node
b) External node
c) Final node
d) Internal node
View Answer
Answer: d
Explanation: Nonleaf nodes are also referred to as
internal nodes.
9. Insertion of a
large number of entries at a time into an index is referred to as __________ of
the index.
a) Loading
b) Bulk insertion
c) Bulk loading
d) Increase insertion
View Answer
Answer: c
Explanation: Bulk loading is used to improve the
efficiency and scalability.
10. While inserting
the record into the index, if the search-key value does not appear in the
index.
a) The system adds a
pointer to the new record in the index entry
b) The system places
the record being inserted after the other records with the same search-key
values
c) The system inserts
an index entry with the search-key value in the index at the appropriate
position
d) None of the
mentioned
View Answer
Answer: c
Explanation: If the index entry stores pointers to all
records with the same search key value, the system adds a pointer to the new
record in the index entry.
1. If h is any
hashing function and is used to hash n keys in to a table of size m, where
n<=m, the expected number of collisions involving a particular key x is :
a) Less than 1
b) Less than n
c) Less than m
d) Less than n/2
View Answer
Answer: a
Explanation: Hashing is also a method of sorting key
values in a database table in an efficient manner.
2. A technique for
direct search is
a) Binary Search
b) Linear Search
c) Tree Search
d) Hashing
View Answer
Answer: d
Explanation: Hashing is one way to enable security during
the process of message transmission when the message is intended for a
particular recipient only.
3. The searching
technique that takes O (1) time to find a data is
a) Linear Search
b) Binary Search
c) Hashing
d) Tree Search
View Answer
Answer: c
Explanation: A formula generates the hash, which helps to
protect the security of the transmission from unauthorized users.
4. The goal of
hashing is to produce a search that takes
a) O(1) time
b) O(n2 )time
c) O(log n ) time
d) O(n log n ) time
View Answer
Answer: a
Explanation: Time complexity is given by the big oh
notation.
5. Consider a hash
table of size seven, with starting index zero, and a hash function (3x +
4)mod7. Assuming the hash table is initially empty, which of the following is
the contents of the table when the sequence 1, 3, 8, 10 is inserted into the
table using closed hashing? Note that ‘_’ denotes an empty location in the
table.
a) 8, _, _, _, _, _,
10
b) 1, 8, 10, _, _, _,
3
c) 1, _, _, _, _, _,3
d) 1, 10, 8, _, _, _,
3
View Answer
Answer: b
Explanation: A formula generates the hash, which helps to
protect the security of the transmission from unauthorized users.
6. A hash table can
store a maximum of 10 records, currently there are records in location 1,
3,4,7,8,9,10. The probability of a new record going into location 2, with hash
functions resolving collisions by linear probing is
a) 0.1
b) 0.6
c) 0.2
d) 0.5
View Answer
Answer: b
Explanation: Hashing is used to index and retrieve items
in a database because it is easier to find the item using the shortened hashed
key than using the original value.
7. Key value pairs is
usually seen in
a) Hash tables
b) Heaps
c) Both Hash tables
and Heaps
d) Skip list
View Answer
Answer: a
Explanation: Hashing is used to index and retrieve items
in a database because it is easier to find the item using the shortened hashed
key than using the original value.
8. What is the best
definition of a collision in a hash table?
a) Two entries are
identical except for their keys
b) Two entries with
different data have the exact same key
c) Two entries with
different keys have the same exact hash value
d) Two entries with
the exact same key have different hash values
View Answer
Answer: a
Explanation: This level is the root of the tree.
9. Which of the
following scenarios leads to linear running time for a random search hit in a
linear-probing hash table?
a) All keys hash to
same index
B) All keys hash to
different indices
c) All keys hash to
an even-numbered index
d) All keys hash to
different even-numbered indices
View Answer
Answer: a
Explanation: If all keys hash to the same location then
the i-th inserted key would need i lookups to be found. The probability of
looking up i-th key is 1/n (since it’s random). If you know some probability
it’s trivial to show that such lookups have linear time.
10. Breadth First
Search is used in
a) Binary trees
b) Stacks
c) Graphs
d) All of the
mentioned
View Answer
Answer: c
Explanation: Hashing is used to index and retrieve items
in a database because it is easier to find the item using the shortened hashed
key than using the original value.
1. A(n) _________ can
be used to preserve the integrity of a document or a message.
a) Message digest
b) Message summary
c) Encrypted message
d) None of the
mentioned
View Answer
Answer: c
Explanation: Encryption algorithms are used to keep the
contents safe.
2. A hash function
must meet ________ criteria.
a) Two
b) Three
c) Four
d) None of the
mentioned
View Answer
Answer: b
Explanation: Only if the criteria is fulfilled the values
are hashed.
3. What is the main limitation
of Hierarchical Databases?
a) Limited capacity
(unable to hold much data)
b) Limited
flexibility in accessing data
c) Overhead
associated with maintaining indexes
d) The performance of
the database is poor
View Answer
Answer: b
Explanation: In this the data items are place in a tree
like hierarchical structure.
4. The property (or
set of properties) that uniquely defines each row in a table is called the:
a) Identifier
b) Index
c) Primary key
d) Symmetric key
View Answer
Answer: c
Explanation: Primary is used to uniquely identify the
tuples.
5. The separation of
the data definition from the program is known as:
a) Data dictionary
b) Data independence
c) Data integrity
d) Referential
integrity
View Answer
Answer: b
Explanation: Data dictionary is the place where the
meaning of the data are organized.
6. In the client /
server model, the database:
a) Is downloaded to
the client upon request
b) Is shared by both
the client and server
c) Resides on the
client side
d) Resides on the
server side
View Answer
Answer: d
Explanation: The server has all the database information
and the client access it.
7. The traditional
storage of data that is organized by customer, stored in separate folders in
filing cabinets is an example of what type of ‘database’ system?
a) Hierarchical
b) Network
c) Object oriented
d) Relational
View Answer
Answer: a
Explanation: Hierarchy is based on Parent-Child
Relationship. Parent-Child Relationship Type is basically 1:N relationship.
8. The database
design that consists of multiple tables that are linked together through
matching data stored in each table is called
a) Hierarchical
database
b) Network database
c) Object oriented
database
d) Relational
database
View Answer
Answer: d
Explanation: A relational database is a collection of
data items organized as a set of formally described tables from which data can
be accessed or reassembled.
9. The association
role defines:
a) How tables are
related in the database
b) The relationship
between the class diagram and the tables in the database
c) The tables that
each attribute is contained
d) Which attribute is
the table’s primary key
View Answer
Answer: a
Explanation: The tables are always related in the
database to form consistency.
10. The purpose of an
N-Ary association is:
a) To capture a
parent-child relationship
b) To deal with one
to many relationships
c) To deal with
relationships that involve more than two tables
d) To represent an
inheritance relationship
View Answer
Answer: c
Explanation: The is binary n-array association meaning
more than two classes are involved in the relationship.
1. A(n) _________ can
be used to preserve the integrity of a document or a message.
a) Message digest
b) Message summary
c) Encrypted message
d) None of the
mentioned
View Answer
Answer: c
Explanation: Encryption algorithms are used to keep the
contents safe.
2. A hash function
must meet ________ criteria.
a) Two
b) Three
c) Four
d) None of the
mentioned
View Answer
Answer: b
Explanation: Only if the criteria is fulfilled the values
are hashed.
3. What is the main
limitation of Hierarchical Databases?
a) Limited capacity
(unable to hold much data)
b) Limited
flexibility in accessing data
c) Overhead
associated with maintaining indexes
d) The performance of
the database is poor
View Answer
Answer: b
Explanation: In this the data items are place in a tree
like hierarchical structure.
4. The property (or
set of properties) that uniquely defines each row in a table is called the:
a) Identifier
b) Index
c) Primary key
d) Symmetric key
View Answer
Answer: c
Explanation: Primary is used to uniquely identify the
tuples.
5. The separation of
the data definition from the program is known as:
a) Data dictionary
b) Data independence
c) Data integrity
d) Referential
integrity
View Answer
Answer: b
Explanation: Data dictionary is the place where the
meaning of the data are organized.
6. In the client /
server model, the database:
a) Is downloaded to
the client upon request
b) Is shared by both
the client and server
c) Resides on the
client side
d) Resides on the
server side
View Answer
Answer: d
Explanation: The server has all the database information
and the client access it.
7. The traditional
storage of data that is organized by customer, stored in separate folders in
filing cabinets is an example of what type of ‘database’ system?
a) Hierarchical
b) Network
c) Object oriented
d) Relational
View Answer
Answer: a
Explanation: Hierarchy is based on Parent-Child
Relationship. Parent-Child Relationship Type is basically 1:N relationship.
8. The database
design that consists of multiple tables that are linked together through
matching data stored in each table is called
a) Hierarchical
database
b) Network database
c) Object oriented
database
d) Relational
database
View Answer
Answer: d
Explanation: A relational database is a collection of
data items organized as a set of formally described tables from which data can
be accessed or reassembled.
9. The association
role defines:
a) How tables are
related in the database
b) The relationship
between the class diagram and the tables in the database
c) The tables that
each attribute is contained
d) Which attribute is
the table’s primary key
View Answer
Answer: a
Explanation: The tables are always related in the
database to form consistency.
10. The purpose of an
N-Ary association is:
a) To capture a
parent-child relationship
b) To deal with one
to many relationships
c) To deal with relationships
that involve more than two tables
d) To represent an
inheritance relationship
View Answer
Answer: c
Explanation: The is binary n-array association meaning
more than two classes are involved in the relationship.
1. Bitmap indices are
a specialized type of index designed for easy querying on ___________
a) Bit values
b) Binary digits
c) Multiple keys
d) Single keys
View Answer
Answer: c
Explanation: Each bitmap index is built on a single key.
2. A _______ on the
attribute A of relation r consists of one bitmap for each value that A can
take.
a) Bitmap index
b) Bitmap
c) Index
d) Array
View Answer
Answer: a
Explanation: A bitmap is simply an array of bits.
3.
SELECT *
FROM r
WHERE gender = ’f’
AND income level = ’L2’;
In this selection, we
fetch the bitmaps for gender value f and the bitmap for income level value L2,
and perform an ________ of the two bitmaps.
a) Union
b) Addition
c) Combination
d) Intersection
View Answer
Answer: d
Explanation: We compute a new bitmap where bit i has value
1 if the ith bit of the two bitmaps are both 1, and has a value 0 otherwise.
4. To identify the
deleted records we use the ______________
a) Existence bitmap
b) Current bitmap
c) Final bitmap
d) Deleted bitmap
View Answer
Answer: a
Explanation: The bitmaps which are deleted are denoted by
0.
5. Bitmaps can be
used as a compressed storage mechanism at the leaf nodes of ________ for those
values that occur very frequently.
a) B-trees
b) B+-trees
c) Bit trees
d) Both B-trees and
B+-trees
View Answer
Answer: b
Explanation: Bitmaps are combined and stored in a B+
tree.
6. Bitmaps can be
combined with regular B+-tree indices for relations where a few attribute
values are extremely common, and other values also occur, but much less
frequently.
a) Bitmap, B-tree
b) Bitmap, B+tree
c) B-tree, Bitmap
d) B+tree, Bitmap
View Answer
Answer: b
Explanation: Bitmaps are combined and stored in a B+
tree.
7. In a B+-tree index
______ for each value we would normally maintain a list of all records with
that value for the indexed attribute.
a) Leaf
b) Node
c) Root
d) Link
View Answer
Answer: a
Explanation: Bitmaps are combined and stored in a B+
tree.
8. A tablespace is
further broken down into ________
a) Tablespace
b) Segments
c) Extents
d) Blocks
View Answer
Answer: b
Explanation: Segment names are used in create table and
create index commands to place tables or indexes on specific database devices.
9. In ordered indices
the file containing the records is sequentially ordered, a ___________ is an
index whose search key also defines the sequential order of the file.
a) Clustered index
b) Structured index
c) Unstructured index
d) Nonclustered index
View Answer
Answer: a
Explanation: Clustering index are also called primary
indices; the term primary index may appear to denote an index on a primary key,
but such indices can in fact be built on any search key.
10. Indices whose
search key specifies an order different from the sequential order of the file
are called ___________ indices.
a) Nonclustered
b) Secondary
c) All of the
mentioned
d) None of the
mentioned
View Answer
Answer: c
Explanation: Nonclustering index are also called
secondary indices.
1. What is the
purpose of index in sql server
a) To enhance the
query performance
b) To provide an
index to a record
c) To perform fast
searches
d) All of the
mentioned
View Answer
Answer: d
Explanation: A database index is a data structure that
improves the speed of data retrieval operations on a database table at the cost
of additional writes.
2. How many types of indexes
are there in sql server?
a) 1
b) 2
c) 3
d) 4
View Answer
Answer: b
Explanation: They are clustered index and non clustered
index.
3. How non clustered
index point to the data?
a) It never points to
anything
b) It points to a
data row
c) It is used for
pointing data rows containing key values
d) None of the
mentioned
View Answer
Answer: c
Explanation: Nonclustered indexes have a structure
separate from the data rows. A nonclustered index contains the nonclustered
index key values and each key value entry has a pointer to the data row that
contains the key value.
4. Which one is true
about clustered index?
a) Clustered index is
not associated with table
b) Clustered index is
built by default on unique key columns
c) Clustered index is
not built on unique key columns
d) None of the
mentioned
View Answer
Answer: b
Explanation: Nonclustered indexes have a structure
separate from the data rows. A nonclustered index contains the nonclustered
index key values and each key value entry has a pointer to the data row that
contains the key value.
5. What is true about
indexes?
a) Indexes enhance
the performance even if the table is updated frequently
b) It makes harder
for sql server engines to work to work on index which have large keys
c) It doesn’t make
harder for sql server engines to work to work on index which have large keys
d) None of the
mentioned
View Answer
Answer: b
Explanation: Indexes tend to improve the performance.
6. Does index take
space in the disk ?
a) It stores memory
as and when required
b) Yes, Indexes are
stored on disk
c) Indexes are never
stored on disk
d) Indexes take no
space
View Answer
Answer: b
Explanation: Indexes take memory slots which are located
on the disk.
7. What are composite
indexes ?
a) Are those which
are composed by database for its internal use
b) A composite index
is a combination of index on 2 or more columns
c) Composite index
can never be created
d) None of the
mentioned
View Answer
Answer: b
Explanation: A composite index is an index on two or more
columns of a table.
8. If an index is
_________________ the metadata and statistics continue to exists
a) Disabling
b) Dropping
c) Altering
d) Both Disabling and
Dropping
View Answer
Answer: a
Explanation: A database index is a data structure that
improves the speed of data retrieval operations on a database table at the cost
of additional writes.
9. In _______________
index instead of storing all the columns for a record together, each column is
stored separately with all other rows in an index.
a) Clustered
b) Column store
c) Non clustered
d) Row store
View Answer
Answer: b
Explanation: A database index is a data structure that
improves the speed of data retrieval operations on a database table at the cost
of additional writes.
10. A
_________________ index is the one which satisfies all the columns requested in
the query without performing further lookup into the clustered index.
a) Clustered
b) Non Clustered
c) Covering
d) B-Tree
View Answer
Answer: c
Explanation: A covered query is a query where all the
columns in the query’s result set are pulled from non-clustered indexes.
1. A collection of
data designed to be used by different people is called a/an
a) Organization
b) Database
c) Relationship
d) Schema
View Answer
Answer: b
Explanation: Database is a collection of related tables.
2. Which of the
following is the oldest database model?
a) Relational
b) Deductive
c) Physical
d) Network
View Answer
Answer: d
Explanation: The network model is a database model
conceived as a flexible way of representing objects and their relationships.
3. Which of the
following schemas does define a view or views of the database for particular
users?
a) Internal schema
b) Conceptual schema
c) Physical schema
d) External schema
View Answer
Answer: d
Explanation: An externally-defined schema can provide
access to tables that are managed on any PostgreSQL, Microsoft SQL Server, SAS,
Oracle, or MySQL database.
4. Which of the
following is an attribute that can uniquely identify a row in a table?
a) Secondary key
b) Candidate key
c) Foreign key
d) Alternate key
View Answer
Answer: b
Explanation: A Candidate Key can be any column or a
combination of columns that can qualify as unique key in database.
5. Which of the
following is the process of selecting the data storage and data access
characteristics of the database?
a) Logical database
design
b) Physical database
design
c) Testing and
performance tuning
d) Evaluation and
selecting
View Answer
Answer: b
Explanation: The physical design of the database
optimizes performance while ensuring data integrity by avoiding unnecessary
data redundancies.
6. Which of the
following terms does refer to the correctness and completeness of the data in a
database?
a) Data security
b) Data constraint
c) Data independence
d) Data integrity
View Answer
Answer: d
Explanation: ACID property is satisfied by transaction in
database.
7. The relationship
between DEPARTMENT and EMPLOYEE is a
a) One-to-one
relationship
b) One-to-many
relationship
c) Many-to-many
relationship
d) Many-to-one
relationship
View Answer
Answer: b
Explanation: One entity department is related to several
employees.
8. A table can be
logically connected to another table by defining a
a) Super key
b) Candidate key
c) Primary key
d) Unique key
View Answer
Answer: c
Explanation: A superkey is a combination of attributes
that can be uniquely used to identify a database record.
9. If the state of
the database no longer reflects a real state of the world that the database is
supposed to capture, then such a state is called
a) Consistent state
b) Parallel state
c) Durable state
d) Inconsistent state
View Answer
Answer: d
Explanation: SQL data consistency is that whenever a
transaction is performed, it sees a consistent database.
10. Ensuring
isolation property is the responsibility of the
a)
Recovery-management component of the DBMS
b)
Concurrency-control component of the DBMS
c)
Transaction-management component of the DBMS
d) Buffer management
component in DBMS
View Answer
Answer: b
Explanation: Concurrency control ensures that correct
results for concurrent operations are generated, while getting those results as
quickly as possible.
1. In query
processing, the ___________ is the lowest-level operator to access data.
a) Index Search
b) Linear search
c) File scan
d) Access paths
View Answer
Answer: c
Explanation: File scans are search algorithms that locate
and retrieve records that fulfill a selection condition.
2. In a ____________
the system scans each file block and tests all records to see whether they
satisfy the selection condition.
a) Index Search
b) Linear search
c) File scan
d) Access paths
View Answer
Answer: b
Explanation: An initial seek is required to access the
first block of the file.
3. Index structures
are referred to as __________ since they provide a path through which data can
be located and accessed.
a) Index Search
b) Linear search
c) File scan
d) Access paths
View Answer
Answer: d
Explanation: A primary index is an index that allows the
records of a file to be read in an order that corresponds to the physical order
in the file.
4. Search algorithms
that use an index are referred to as
a) Index Search
b) Linear search
c) File scan
d) Access paths
View Answer
Answer: a
Explanation: Selection predicates are used to guide in
the choice of the index to use in processing the query.
5. Which algorithm
uses equality comparison on a key attribute with a primary index to retrieve a
single record that satisfies the corresponding equality condition.
a) A2
b) A4
c) A5
d) A6
View Answer
Answer: a
Explanation: A2 – primary index, equality on key.
6. The strategy can
retrieve a single record if the equality condition is on a key;multiple records
may be retrieved if the indexing field is not a key is
a) A2
b) A4
c) A5
d) A6
View Answer
Answer: b
Explanation: A4 – Secondary index, equality.
7. The algorithm that
uses a secondary ordered index to guide retrieval for comparison conditions
involving <,≤,≥, or > is
a) A2
b) A4
c) A5
d) A6
View Answer
Answer: d
Explanation: A6 – Secondary index, comparison.
8. The ___ algorithm
scans each index for pointers to tuples that satisfy an individual condition.
a) A2
b) A4
c) A9
d) A6
View Answer
Answer: c
Explanation: A9 – Conjunctive selection by intersection
of identifiers.
9. If access paths
are available on all the conditions of a disjunctive selection, each index is
scanned for pointers to tuples that satisfy the individual condition. This is
satisfied by
a) A10
b) A7
c) A9
d) A6
View Answer
Answer: a
Explanation: A10 – Disjunctive selection by union of identifiers.
10. Conjunctive
selection using one index. This is
a) A10
b) A7
c) A9
d) A6
View Answer
Answer: b
Explanation: To reduce the cost of A7 we choose a _i and
one of algorithms A1 through A6 for which the combination results in the least
cost for __i (r ). The cost of algorithm A7 is given by the cost of the chosen
algorithm.
1. Two main measures
for the efficiency of an algorithm are
a) Processor and
memory
b) Complexity and
capacity
c) Time and space
d) Data and space
View Answer
Answer: c
Explanation: Depending on the time and space complexity
only the algorithm for sorting will be chosen.
2. The time factor
when determining the efficiency of algorithm is measured by
a) Counting
microseconds
b) Counting the
number of key operations
c) Counting the
number of statements
d) Counting the
kilobytes of algorithm
View Answer
Answer: b
Explanation: The operations taking place with the time
and space is counted.
3. The space factor
when determining the efficiency of algorithm is measured by
a) Counting the
maximum memory needed by the algorithm
b) Counting the
minimum memory needed by the algorithm
c) Counting the
average memory needed by the algorithm
d) Counting the
maximum disk space needed by the algorithm
View Answer
Answer: a
Explanation: Time complexity maintains the maximum time
needed.
4. Which of the
following case does not exist in complexity theory
a) Best case
b) Worst case
c) Average case
d) Null case
View Answer
Answer: d
Explanation: Null case cannot be counted as the factor
for complexity.
5. The Worst case
occur in linear search algorithm when
a) Item is somewhere
in the middle of the array
b) Item is not in the
array at all
c) Item is the last
element in the array
d) Item is the last
element in the array or is not there at all
View Answer
Answer: d
Explanation: Algorithmic complexity is concerned about
how fast or slow particular algorithm performs.
6. The Average case
occur in linear search algorithm
a) When Item is
somewhere in the middle of the array
b) When Item is not
in the array at all
c) When Item is the
last element in the array
d) When Item is the
last element in the array or is not there at all
View Answer
Answer: a
Explanation: Algorithmic complexity is concerned about how
fast or slow particular algorithm performs.
7. The complexity of
the average case of an algorithm is
a) Much more
complicated to analyze than that of worst case
b) Much more simpler
to analyze than that of worst case
c) Sometimes more
complicated and some other times simpler than that of worst case
d) None of the
mentioned
View Answer
Answer: a
Explanation: Algorithmic complexity is concerned about
how fast or slow particular algorithm performs.
8. The complexity of
linear search algorithm is
a) O(n)
b) O(log n)
c) O(n2)
d) O(n log n)
View Answer
Answer: a
Explanation: It refers to n values complexity in the
algorithm which can be reduced by choosing the other algorithms.
9. The complexity of
Binary search algorithm is
a) O(n)
b) O(log )
c) O(n2)
d) O(n log n)
View Answer
Answer: b
Explanation: This shows that it has a standard complexity
in addressing.
10. The complexity of
Bubble sort algorithm is
a) O(n)
b) O(log n)
c) O(n2)
d) O(n log n)
View Answer
Answer: c
Explanation: Bubble sort, is a simple sorting algorithm
that works by repeatedly stepping through the list to be sorted, comparing each
pair of adjacent items and swapping them if they are in the wrong order.
1. A_____ is a query
that retrieves rows from more than one table or view:
a) Start
b) End
c) Join
d) All of the
mentioned
View Answer
Answer: c
Explanation: An SQL join clause combines records from two
or more tables in a database. It creates a set that can be saved as a table or
used as it is. A JOIN is a means for combining fields from two tables by using
values common to each.
2. A condition is
referred to as __________
a) Join in SQL
b) Join condition
c) Join in SQL &
Condition
d) None of the
mentioned
View Answer
Answer: b
Explanation: An SQL join clause combines records from two
or more tables in a database. It creates a set that can be saved as a table or
used as it is. A JOIN is a means for combining fields from two tables by using
values common to each.
3. Which oracle is
the join condition is specified using the WHERE clause:
a) Oracle 9i
b) Oracle 8i
c) Pre-oracle 9i
d) Pre-oracle 8i
View Answer
Answer: c
Explanation: Oracle 9i is a version of the Oracle
Database. The i stands for “Internet” to indicate that 9i is “Internet ready”.
4. How many join
types in join condition:
a) 2
b) 3
c) 4
d) 5
View Answer
Answer: d
Explanation: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL
JOIN, EQUIJOIN.
5. Which are the join
types in join condition:
a) Cross join
b) Natural join
c) Join with USING
clause
d) All of the
mentioned
View Answer
Answer: d
Explanation: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL
JOIN, EQUIJOIN are the types of joins.
6. Which product is
returned in a join query have no join condition:
a) Equijoins
b) Cartesian
c) Both Equijoins and
Cartesian
d) None of the
mentioned
View Answer
Answer: b
Explanation: A Cartesian coordinate system is a
coordinate system that specifies each point uniquely in a plane by a pair of
numerical coordinates.
7. Which is a join
condition contains an equality operator:
a) Equijoins
b) Cartesian
c) Both Equijoins and
Cartesian
d) None of the
mentioned
View Answer
Answer: a
Explanation: An equi-join is a specific type of
comparator-based join, that uses only equality comparisons in the
join-predicate.
8. Which join refers
to join records from the write table that have no matching key in the left
table are include in the result set:
a) Left outer join
b) Right outer join
c) Full outer join
d) Half outer join
View Answer
Answer: b
Explanation: A right outer join will return all the rows
that an inner join returns plus one row for each of the other rows in the
second table that did not have a match in the first table. It is the same as a
left outer join with the tables specified in the opposite order.
9. Which operation
are allowed in a join view:
a) UPDATE
b) INSERT
c) DELETE
d) All of the
mentioned
View Answer
Answer: d
Explanation: The DELETE statement is used to delete rows
in a table.The UPDATE statement is used to update existing records in a
table.The INSERT INTO statement is used to insert new records in a table.
10. Which view that
contains more than one table in the top-level FROM clause of the SELECT
statement:
a) Join view
b) Datable join view
c) Updatable join
view
d) All of the mentioned
View Answer
Answer: c
Explanation: The DELETE statement is used to delete rows
in a table.The UPDATE statement is used to update existing records in a
table.The INSERT INTO statement is used to insert new records in a table.
1. Pictorial
representation of an expression is called
a) Expression tree
b) Operator tree
c) Expression flow
d) Expression chart
View Answer
Answer: b
Explanation: The operator tree has a tree like format
where the evaluation starts from root of the tree .
2. The results of each
intermediate operation are created and then are used for evaluation of the
next-level operations. This is called
a) Materialized
evaluation
b) Expression
evaluation
c) Tree evaluation
d) Tree
materialization
View Answer
Answer: a
Explanation: The cost of a materialized evaluation is not
simply the sum of the costs of the operations involved .
3. ______________
allows the algorithm to execute more quickly by performing CPU activity in
parallel with I/O activity.
a) Buffering
b) Double buffering
c) Multiple buffering
d) Double reading
View Answer
Answer: a
Explanation: Double buffering using two buffers, with one
continuing execution of the algorithm while the other is being written out .
4. Pipelines can be
executed in
a) 4
b) 3
c) 2
d) 5
View Answer
Answer: c
Explanation: Demand driven and producer driven pipelines
are the two ways .
5. In a _________ the
system makes repeated requests for tuples from the operation at the top of the
pipeline.
a) Demand-driven
pipeline
b) Producer-driven
pipeline
c) Demand pipeline
d) All of the
mentioned
View Answer
Answer: a
Explanation: Each time that an operation receives a
request for tuples, it computes the next tuple (or tuples) to be returned, and
then returns that tuple .
6. In a _____________
operations do not wait for requests to produce tuples, but instead generate the
tuples eagerly.
a) Demand-driven
pipeline
b) Producer-driven
pipeline
c) Demand pipeline
d) All of the
mentioned
View Answer
Answer: b
Explanation: Each operation in a producer-driven pipeline
is modeled as a separate process or thread within the system that takes a
stream of tuples from its pipelined inputs and generates a stream of tuples for
its output.
7. Each operation in
a demand-driven pipeline can be implemented as an ____ that provides the
following functions: open(), next(), and close().
a) Demand
b) Pipeline
c) Iterator
d) All of the
mentioned
View Answer
Answer: c
Explanation: After a call to open(), each call to next()
returns the next output tuple of the operation.
8. The iterator
maintains the __________ of its execution in between calls, so that successive
next() requests receive successive result tuples.
a) State
b) Transition
c) Rate
d) Block
View Answer
Answer: a
Explanation: The function close() tells an iterator that
no more tuples are required.
9. Tuples are
generated ___________ in producer-driven pipelining, they are generated
________ on demand, in demand-driven pipelining.
a) Lazily, Eagerly
b) Eagerly, Lazily
c) Slowly, Eagerly
d) Eagerly, Slowly
View Answer
Answer: b
Explanation: Producer-driven pipelining is very useful in
parallel processing systems.
10. When two inputs
that we desire to pipeline into the join are not already sorted it is the
_____________ technique.
a) Hash join
b) Buffer join
c) double-pipelined
hash join
d) double-pipelined
join
View Answer
Answer: d
Explanation: When hash indices are used on tuples, the
resultant algorithm is called the double-pipelined hash-join technique..
3. Which of the
following is/are false for RAW mode of FOR XML?
a) XMLSCHEMA option
does not returns an in-line XSD schema
b) BINARY BASE32
returns the binary data in base32-encoded format
c) Each row in the
query result is transformed into an XML element
d) None of the
mentioned
View Answer
Answer: b
Explanation: XML was designed to transport and store
data.
4. ___________ refers
to the ability of the system to recover committed transaction updates if either
the system or the storage media fails.
a) Isolation
b) Atomicity
c) Consistency
d) Durability
View Answer
Answer: d
Explanation: In database systems, durability is the ACID
property which guarantees that transactions that have committed will survive
permanently.
5. Which utilities
can we used to export data from sql server to a text file?
a) DTS export wizard
b) BCP
c) ISQL
d) DTS export wizard
and BCP
View Answer
Answer: d
Explanation: The bcp utility bulk copies data between an
instance of Microsoft SQL Server and a data file in a user-specified format.
6. You have a column
that will only contain values from 0 to 256. What is the most economical data
type to use for the column?
a) TINYINT
b) SMALLINT
c) INT
d) DECIMAL(1)
View Answer
Answer: b
Explanation: The bcp utility bulk copies data between an
instance of Microsoft SQL Server and a data file in a user-specified format.
7. Problems occurs if
we don’t implement proper locking strategy
a) Dirty reads
b) Phantom reads
c) Lost updates
d) Unrepeatable reads
View Answer
Answer: b
Explanation: Phantom reads occur when an insert or delete
action is performed against a row that belongs to a range of rows being read by
a transaction.
8. Which of the
following fixed database roles can add or remove user IDs?
a) db_accessadmin
b) db_securityadmin
c) db_setupadmin
d) db_sysadmin
View Answer
Answer: a
Explanation: The db_accessadmin role manages security,
but handles access to the database, as the name implies.
9. By default sql
server has ___________ isolation level
a) READ COMMITTED
b) READ UNCOMMITTED
c) SERIALIZABLE
d) REPEATABLE READ
View Answer
Answer: a
Explanation: READ UNCOMMITTED is the most optimistic
concurrency isolation option available in SQL Server.
10. Which of the
following pair of regular expression are not equivalent?
a) 1(01)* and (10)*1
b) x(xx)* and (xx)*x
c) (ab)* and a*b*
d) x+ and x*x+
View Answer
Answer: c
Explanation: (ab)*=(a*b*)*.
1. Which feature
converts row data to column for better analytical view?
a) Views
b) Join
c) Pivot
d) Trigger
View Answer
Answer: c
Explanation: Pivot table is very powerful, and very easy
to use.
2. Which of the
following statements is/are not true for SQL profiler?
a) Enables you to
monitor events
b) Check if rows are
being inserted properly
c) Check the
performance of a stored procedure
d) None of the
mentioned
View Answer
Answer: c
Explanation: Stored procedures are like functions which
do not return values.
3. Which global
variables can be used to determine if a transaction is still open?
a) @@NESTLEVEL
b) @@FETCH_STATUS
c) @@TRANCOUNT
d) @@CONNECTIONS
View Answer
Answer: c
Explanation: PRINT @@TRANCOUNT — The BEGIN TRAN statement
will increment the — transaction count by 1.
4. Which statement is
used to define a cursor?
a) OPEN
b) FETCH
c) DECLARE CURSOR
d) @@FETCH_STATUS
View Answer
Answer: c
Explanation: A database cursor is a control structure
that enables traversal over the records in a database.
5. What is the
default “SORT” order for a SQL?
a) Ascending
b) Descending
c) As specified by
the user
d) None of the
mentioned
View Answer
Answer: a
Explanation: Default is ascending order.
6. Capabilities of
RAISERROR
a) It can be logged
in the error log
b) It can print a
message to the application
c) It can assign an
error number, state and severity
d) All of the
mentioned
View Answer
Answer: d
Explanation: A relational database table is often
described as “normalized” if it is in the Third Normal Form because most of the
3NF tables are free of insertion, update, and deletion anomalies.
7. How inserting data
through stored procedure do reduces network traffic and increase database
performance?
a) Stored procedure
can accept parameter
b) Permission check
is not required
c) The execution plan
is stored in the cache after it was executed the first time
d) None of the
mentioned
View Answer
Answer: c
Explanation: A relational database table is often
described as “normalized” if it is in the Third Normal Form because most of the
3NF tables are free of insertion, update, and deletion anomalies.
8. Stored procedures
are safe from SQL injection attacks
a) True
b) False
c) Depends on the
result
d) Always safe
View Answer
Answer: a
Explanation: Injection attack is not possible in SP.
9. Which of the
following connection type supports application role permissions and password
encryption?
a) OLE DB
b) DBLib
c) ODBC
d) OLE DB and ODBC
View Answer
Answer: d
Explanation: Open Database Connectivity (ODBC) is
Microsoft’s strategic interface for accessing data in a heterogeneous
environment of relational.
10. Cursor that
reflects the changes made to the database table even after the result set is
returned
a) Static
b) Dynamic
c) FORWARD_ONLY
d) Keyset
View Answer
Answer: b
Explanation: A database cursor is a control structure
that enables traversal over the records in a database.
1. Which normal form
is considered adequate for normal relational database design?
a) 2NF
b) 5NF
c) 4NF
d) 3NF
View Answer
Answer: d
Explanation: A relational database table is often
described as “normalized” if it is in the Third Normal Form because most of the
3NF tables are free of insertion, update, and deletion anomalies.
2. Consider a schema
R(A, B, C, D) and functional dependencies A -> B and C -> D. Then the
decomposition of R into R1 (A, B) and R2(C, D) is
a) dependency
preserving and lossless join
b) lossless join but
not dependency preserving
c) dependency
preserving but not lossless join
d) not dependency
preserving and not lossless join
View Answer
Answer: d
Explanation: While decomposing a relational table we must
verify the following properties:
i) Dependency
Preserving Property
ii) Lossless-Join
Property.
3. Relation R with an
associated set of functional dependencies, F, is decomposed into BCNF. The
redundancy (arising out of functional dependencies) in the resulting set of
relations is
a) Zero
b) More than zero but
less than that of an equivalent 3NF decomposition
c) Proportional to
the size of F+
d) Indeterminate
View Answer
Answer: b
Explanation: Redundancy in BCNF is low when compared to
3NF.
4. Which one of the
following statements about normal forms is FALSE?
a) BCNF is stricter
than 3NF
b) Lossless,
dependency-preserving decomposition into 3NF is always possible
c) Lossless,
dependency-preserving decomposition into BCNF is always possible
d) Any relation with
two attributes is in BCNF
View Answer
Answer: c
Explanation: Achieving Lossless and dependency-preserving
decomposition property into BCNF is difficult.
5. A table has fields
F1, F2, F3, F4, and F5, with the following functional dependencies:
F1->F3
F2->F4
(F1,F2)->F5
in terms of
normalization, this table is in
a) 1NF
b) 2NF
c) 3NF
d) None of the
mentioned
View Answer
Answer: a
Explanation: Since the primary key is not given we have
to derive the primary key of the table. Using the closure set of attributes we
get the primary key as (F1,F2). From functional dependencies, “F1->F3,
F2->F4”, we can see that there is partial functional dependency therefore it
is not in 1NF. Hence the table is in 1NF.
6. Which of the
following is TRUE?
a) Every relation in
2NF is also in BCNF
b) A relation R is in
3NF if every non-prime attribute of R is fully functionally dependent on every
key of R
c) Every relation in
BCNF is also in 3NF
d) No relation can be
in both BCNF and 3NF
View Answer
Answer: c
Explanation: A relational database table is often
described as “normalized” if it is in the Third Normal Form because most of the
3NF tables are free of insertion, update, and deletion anomalies.
7. Consider the
following functional dependencies in a database.
Date_of_Birth->Age Age->Eligibility
Name->Roll_number Roll_number->Name
Course_number->Course_name Course_number->Instructor
(Roll_number, Course_number)->Grade
The relation
(Roll_number, Name, Date_of_birth, Age) is
a) In second normal
form but not in third normal form
b) In third normal
form but not in BCNF
c) In BCNF
d) None of the
mentioned
View Answer
Answer: d
Explanation: For the given relation only some of the
above FDs are applicable. The applicable FDs are given below:
Date_of_Birth->Age
Name->Roll_number
Roll_number->Name
Finding the closure
set of attributes we get the candidate keys:(Roll_number,Date_of_Birth), and
(Name,Date_of_Birth) .
On selecting any one
of the candidate key we can see that the FD Date_of_Birth->Age is a partial
dependency. Hence the relation is in 1NF.
8. The relation
schema Student_Performance (name, courseNo, rollNo, grade) has the following
FDs:
name,courseNo->grade
rollNo,courseNo->grade
name->rollNo
rollNo->name
The highest normal
form of this relation scheme is
a) 2NF
b) 3NF
c) BCNF
d) 4NF
View Answer
Answer: b
Explanation: A super key is a combination of prime
attributes and one or more non-prime key attribute(s). It also uniquely
identifies a record in a table. Primary key can be defined as super key with
minimal attributes.
9. The relation
EMPDT1 is defined with attributes empcode(unique), name, street, city, state,
and pincode. For any pincode,there is only one city and state. Also, for any
given street, city and state, there is just one pincode. In normalization terms
EMPDT1 is a relation in
a) 1NF only
b) 2NF and hence also
in 1NF
c) 3NF and hence also
in 2NF and 1NF
d) BCNF and hence
also in 3NF, 2NF and 1NF
View Answer
Answer: b
Explanation: Empcode is unique, therefore it is the
primary key. Since the primary key consists of a single attribute there will be
no partial dependency, hence the relation is in 2NF.
From the question we
get the FDs as below:
pincode -> city,
state
street,city,state
-> pincode
From the FDs we can
see that there are transitive dependencies, hence the table is not in 3NF.
10. Which one of the
following statements if FALSE?
a) Any relation with
two attributes is in BCNF
b) A relation in
which every key has only one attribute is in 2NF
c) A prime attribute
can be transitively dependent on a key in a 3 NF relation
d) A prime attribute
can be transitively dependent on a key in a BCNF relation
View Answer
Answer: d
Explanation: A table is in 3NF if and only if, for each
of its functional dependencies X -> A, at least one of the following
conditions holds:
* X contains A (that
is, X -> A is trivial functional dependency), or
* X is a superkey, or
* A should be prime
attribute.
1. _______________ is
a procedural extension of Oracle – SQL that offers language constructs similar
to those in imperative programming languages.
a) SQL
b) PL/SQL
c) Advanced SQL
d) PQL
View Answer
Answer: b
Explanation: PL/SQL is an imperative 3GL that was
designed specifically for the seamless processing of SQL commands.
2. ___________
combines the data manipulating power of SQL with the data processing power of
Procedural languages.
a) PL/SQL
b) SQL
c) Advanced SQL
d) PQL
View Answer
Answer: a
Explanation: PL/SQL is an imperative 3GL that was
designed specifically for the seamless processing of SQL commands.
3. _______________
has made PL/SQL code run faster without requiring any additional work on the
part of the programmer.
a) SQL Server
b) My SQL
c) Oracle
d) SQL Lite
View Answer
Answer: c
Explanation: An Oracle database is a collection of data
treated as a unit. The purpose of a database is to store and retrieve related
information.
4. A line of PL/SQL
text contains groups of characters known as
a) Lexical Units
b) Literals
c) Textual Units
d) Identifiers
View Answer
Answer: a
Explanation: Lexical items can be generally understood to
convey a single meaning, much as a lexeme, but are not limited to single words.
5. We use
______________ name PL/SQL program objects and units.
a) Lexical Units
b) Literals
c) Delimiters
d) Identifiers
View Answer
Answer: d
Explanation: The database object name is referred to as
its identifier.
6. A
___________________ is an explicit numeric, character, string or Boolean value
not represented by an identifier.
a) Comments
b) Literals
c) Delimiters
d) Identifiers
View Answer
Answer: b
Explanation: The terms literal and constant value are
synonymous and refer to a fixed data value.
7. If no header is
specified, the block is said to be an _______________ PL/SQL block.
a) Strong
b) Weak
c) Empty
d) Anonymous
View Answer
Answer: d
Explanation: The terms literal and constant value are
synonymous and refer to a fixed data value.
8. _________________
is a sequence of zero or more characters enclosed by single quotes.
a) Integers literal
b) String literal
c) String units
d) String label
View Answer
Answer: b
Explanation: The terms literal and constant value are
synonymous and refer to a fixed data value.
9. In _______________
the management of the password for the account can be handled outside of oracle
such as operating system.
a) Database
Authentication
b) Operating System
Authentication
c) Internal
Authentication
d) External Authentication
View Answer
Answer: b
Explanation: Database management involves the monitoring,
administration, and maintenance of the databases and database groups in your
enterprise.
10. In
________________ of Oracle, the database administrator creates a user account
in the database for each user who needs access.
a) Database
Authentication
b) Operating System
Authentication
c) Internal
Authentication
d) External
Authentication
View Answer
Answer: a
Explanation: Database management involves the monitoring,
administration, and maintenance of the databases and database groups in your
enterprise.
1. Consider money is
transferred from (1)account-A to account-B and (2) account-B to account-A.
Which of the following form a transaction ?
a) Only 1
b) Only 2
c) Both 1 and 2
individually
d) Either 1 or 2
View Answer
Answer: c
Explanation: The term transaction refers to a collection
of operations that form a single logical unit of work.
2. A transaction is
delimited by statements (or function calls) of the form __________
a) Begin transaction
and end transaction
b) Start transaction
and stop transaction
c) Get transaction
and post transaction
d) Read transaction
and write transaction
View Answer
Answer: a
Explanation: The transaction consists of all operations
executed between the begin transaction and end transaction.
3. Identify the
characteristics of transactions
a) Atomicity
b) Durability
c) Isolation
d) All of the
mentioned
View Answer
Answer: d
Explanation: Because of the above three properties,
transactions are an ideal way of structuring interaction with a database.
4. Which of the
following has “all-or-none” property ?
a) Atomicity
b) Durability
c) Isolation
d) All of the
mentioned
View Answer
Answer: a
Explanation: Either all operations of the transaction are
reflected properly in the database, or none are.
5. The database
system must take special actions to ensure that transactions operate properly
without interference from concurrently executing database statements. This
property is referred to as
a) Atomicity
b) Durability
c) Isolation
d) All of the
mentioned
View Answer
Answer: c
Explanation: Even though multiple transactions may
execute concurrently, the system guarantees that, for every pair of transactions
Ti and Tj , it appears to Ti that either Tj finished execution before Ti
started or Tj started execution after Ti finished.
6. The property of
transaction that persists all the crashes is
a) Atomicity
b) Durability
c) Isolation
d) All of the mentioned
View Answer
Answer: b
Explanation: After a transaction completes successfully,
the changes it has made to the database persist, even if there are system
failures.
7. __________ states
that only valid data will be written to the database.
a) Consistency
b) Atomicity
c) Durability
d) Isolation
View Answer
Answer: a
Explanation: If, for some reason, a transaction is
executed that violates the database’s consistency rules, the entire transaction
will be rolled back and the database will be restored to a state consistent
with those rules.
8. Transaction
processing is associated with everything below except
a) Producing detail
summary or exception reports
b) Recording a
business activity
c) Confirming a
action or triggering a response
d) Maintaining a data
View Answer
Answer: c
Explanation: Collections of operations that form a single
logical unit of work are called transactions.
9. The Oracle RDBMS
uses the ____ statement to declare a new transaction start and its properties.
a) BEGIN
b) SET TRANSACTION
c) BEGIN TRANSACTION
d) COMMIT
View Answer
Answer: b
Explanation: Commit is used to store all the
transactions.
10. ____ means that
the data used during the execution of a transaction cannot be used by a second
transaction until the first one is completed.
a) Consistency
b) Atomicity
c) Durability
d) Isolation
View Answer
Answer: d
Explanation: Even though multiple transactions may
execute concurrently, the system guarantees that, for every pair of
transactions Ti and Tj, it appears to Ti that either Tj finished execution
before Ti started or Tj started execution after Ti finished.
1. In SQL, which
command is used to issue multiple CREATE TABLE, CREATE VIEW and GRANT
statements in a single transaction?
a) CREATE PACKAGE
b) CREATE SCHEMA
c) CREATE CLUSTER
d) All of the
mentioned
View Answer
Answer: b
Explanation: A database schema of a database system is
its structure described in a formal language supported by the database
management system and refers to the organization of data as a blueprint of how
a database is constructed.
2. In SQL, the CREATE
TABLESPACE is used
a) To create a place
in the database for storage of scheme objects, rollback segments, and naming
the data files to comprise the tablespace
b) To create a
database trigger
c) To add/rename data
files, to change storage
d) All of the
mentioned
View Answer
Answer: a
Explanation: Triggers are used to initialise the actions
for a activity.
3. Which character
function can be used to return a specified portion of a character string?
a) INSTR
b) SUBSTRING
c) SUBSTR
d) POS
View Answer
Answer: c
Explanation: SUBSTR are used to match the particular
characters in a string.
4. Which of the
following is TRUE for the System Variable $date$?
a) Can be assigned to
a global variable
b) Can be assigned to
any field only during design time
c) Can be assigned to
any variable or field during run time
d) Can be assigned to
a local variable
View Answer
Answer: b
Explanation: A database schema of a database system is
its structure described in a formal language supported by the database
management system and refers to the organization of data as a blueprint of how
a database is constructed.
5. What are the
different events in Triggers?
a) Define, Create
b) Drop, Comment
c) Insert, Update,
Delete
d) Select, Commit
View Answer
Answer: c
Explanation: A database trigger is procedural code that
is automatically executed in response to certain events on a particular table
or view in a database.
6. Which is the
subset of SQL commands used to manipulate Oracle Database Structures, including
tables?
a) Data Definition
Language
b) Data Manipulation
Language
c) Data Described
Language
d) Data Retrieval
Language
View Answer
Answer: a
Explanation: DDL are used to define schema and table
characters.
7. The SQL statement
SELECT SUBSTR(‘123456789’, INSTR(‘abcabcabc’,’b’), 4) FROM EMP; prints
a) 6789
b) 2345
c) 1234
d) 456789
View Answer
Answer: b
Explanation: SUBSTR are used to match the particular
characters in a string.
8. Which of the
following SQL command can be used to modify existing data in a database table?
a) MODIFY
b) UPDATE
c) CHANGE
d) NEW
View Answer
Answer: b
Explanation: Syntax : UPDATE table_name
SET
column1=value1,column2=value2,…
WHERE
some_column=some_value; .
9. When SQL
statements are embedded inside 3GL, we call such a program as
a) Nested query
b) Nested programming
c) Distinct query
d) Embedded SQL
View Answer
Answer: d
Explanation: SQL-99 is the most recent version of
standard SQL prescribed by the ANSI.
10. _______________
provides option for entering SQL queries as execution time, rather than at the
development stage.
a) PL/SQL
b) SQL*Plus
c) SQL
d) Dynamic SQL
View Answer
Answer: d
Explanation: Dynamic SQL enables you to write programs
that reference SQL statements whose full text is not known until runtime.
1. The storage
structure which do not survive system crashes are ______
a) Volatile storage
b) Non-volatile
storage
c) Stable storage
d) Dynamic storage
View Answer
Answer: a
Explanation: Volatile storage, is a computer memory that
requires power to maintain the stored information, in other words it needs
power to reach the computer memory.
2. Storage devices
like tertiary storage , magnetic disk comes under
a) Volatile storage
b) Non-volatile
storage
c) Stable storage
d) Dynamic storage
View Answer
Answer: b
Explanation: Information residing in nonvolatile storage
survives system crashes.
3. For a transaction
to be durable, its changes need to be written to ________ storage.
a) Volatile storage
b) Non-volatile
storage
c) Stable storage
d) Dynamic storage
View Answer
Answer: c
Explanation: Similarly, for a transaction to be atomic,
log records need to be written to stable storage before any changes are made to
the database on disk.
4. The unit of
storage that can store one are more records in a hash file organization are
a) Buckets
b) Disk pages
c) Blocks
d) Nodes
View Answer
Answer: a
Explanation: Buckets are used to store one or more
records in a hash file organization.
5. A ______ file system
is software that enables multiple computers to share file storage while
maintaining consistent space allocation and file content.
a) Storage
b) Tertiary
c) Secondary
d) Cluster
View Answer
Answer: d
Explanation: With a cluster file system, the failure of a
computer in the cluster does not make the file system unavailable.
6. A file produced by
a spreadsheet
a) is generally
stored on disk in an ASCII text format
b) can be used as is
by the DBMS
c) all of the
mentioned
d) none of the
mentioned
View Answer
Answer: a
Explanation: ASCII text format uses the standard text
file for the changing the value.
7. SDL means
_____________
a) Storage Discrete
Language
b) Storage Definition
Language
c) Storage Definition
Localisation
d) Storage Discrete Localisation
View Answer
Answer: b
Explanation: It specifies internal schema and also
mapping between two schemas.
8. Which of the
following is the process of selecting the data storage and data access
characteristics of the database?
a) Logical database design
b) Physical database
design
c) Testing and
performance tuning
d) Evaluation and
selecting
View Answer
Answer: b
Explanation: Physical database design is the process of
selecting the data storage and data access characteristics of the database.
9. Which of the
following is the oldest database model?
a) Relational
b) Hierarchical
c) Physical
d) Network
View Answer
Answer: d
Explanation: Network model has data stored in a
hierarchical network flow.
10. The process of
saving information onto secondary storage devices is referred to as
a) Backing up
b) Restoring
c) Writing
d) Reading
View Answer
Answer: c
Explanation: The information is written into the
secondary storage device.
1. A transaction may
not always complete its execution successfully. Such a transaction is termed
a) Aborted
b) Terminated
c) Closed
d) All of the
mentioned
View Answer
Answer: a
Explanation: If we are to ensure the atomicity property,
an aborted transaction must have no effect on the state of the database.
2. If an transaction
is performed in a database and committed, the changes are taken to the previous
state of transaction by
a) Flashback
b) Rollback
c) Both Flashback and
Rollback
d) Cannot be done
View Answer
Answer: d
Explanation: Once committed the changes cannot be rolled
back.
3. Each modification
done in database transaction are first recorded into the
a) Harddrive
b) Log
c) Disk
d) Datamart
View Answer
Answer: b
Explanation: After commit is issued the data are stored
in database and stored in drive.
4. When the
transaction finishes the final statement the transaction enters into
a) Active state
b) Committed state
c) Partially
committed state
d) Abort state
View Answer
Answer: c
Explanation: The commit statement has to be issued to
enter into committed state.
5. The name of the
transaction file shall be provided by the operator and the file that contains
the edited transactions ready for execution shall be called
a) Batch. Exe
b) Trans. Exe
c) Opt. Exe
d) Edit.Exe
View Answer
Answer: c
Explanation: Transactions has to be managed by the
executable files.
6. Which of the
following is an atomic sequence of database actions?
a) Transaction
b) Concurrency
c) Relations
d) All of the
mentioned
View Answer
Answer: a
Explanation: Transactions is collection of operations
that provides single logical function in database.
7. If the state of
the database no longer reflects a real state of the world that the database is
supposed to capture, then such a state is called
a) Consistent state
b) Parallel state
c) Atomic state
d) Inconsistent state
View Answer
Answer: d
Explanation: If the state of the database no longer
reflects a real state of the world that the database is supposed to capture,
then such a state is called in consistent state.
8. _______ means that
data used during the execution of a transaction cannot be used by a second
transaction until the first one is completed.
a) Serializability
b) Atomicity
c) Isolation
d) Time stamping
View Answer
Answer: c
Explanation: Isolation means that data used during the
execution of a transaction can’t be used by a second transaction until the
first one is completed.
9. DBMS periodically
suspends all processing and synchronizes its files and journals through the use
of
a) Checkpoint
facility
b) Backup facility
c) Recovery manager
d) Database change
log
View Answer
Answer: a
Explanation: DBMS periodically suspends all processing
and synchronizes its files and journals though the use of Check point facility.
10. Which of the
following is not a state in transaction ?
a) Active
b) Terminated
c) Aborted
d) Partially
committed
View Answer
Answer: b
Explanation: The transaction states are
abort,active,committed,partially committed, Failed.
1. _______________
joins are SQL server default
a) Outer
b) Inner
c) Equi
d) None of the
Mentioned
View Answer
Answer: b
Explanation: Inner query joins only the rows that are
matching.
2. The
________________ is essentially used to search for patterns in target string.
a) Like Predicate
b) Null Predicate
c) In Predicate
d) Out Predicate
View Answer
Answer: a
Explanation: Like matches the pattern with the query.
3. Which of the
following is/are the Database server functions?
i) Data management
ii) Transaction management
iii) Compile queries
iv) Query optimization
a) i, ii, and iv only
b) i, ii and iii only
c) ii, iii and iv
only
d) All i, ii, iii,
and iv
View Answer
Answer: a
Explanation: All these are functions of database.
4. To delete a
database ___________ command is used
a) Delete database database_name
b) Delete
database_name
c) drop database
database_name
d) drop database_name
View Answer
Answer: c
Explanation: This will delete the database with its
structure.
5. ____________ is a
combination of two of more attributes used as a primary key
a) Composite Key
b) Alternate Key
c) Candidate Key
d) Foreign Key
View Answer
Answer: a
Explanation: Primary keys together form the composite
key.
6. Which of the
following is not the function of client?
a) Compile queries
b) Query optimization
c) Receive queries
d) Result formatting
and presentation
View Answer
Answer: b
Explanation: Query optimization is used to improve the
quality.
7. ____________ is a
special type of stored procedure that is automatically invoked whenever the
data in the table is modified.
a) Procedure
b) Trigger
c) Curser
d) None of the
Mentioned
View Answer
Answer: b
Explanation: Triggers are used to initiate a action to
take place.
8. ______________
requires that data should be made available to only authorized users.
a) Data integrity
b) Privacy
c) Security
d) None of the
Mentioned
View Answer
Answer: c
Explanation: Some algorithms may be used for the
security.
9. Some of the
utilities of DBMS are _____________
i) Loading ii) Backup
iii) File organization iv) Process Organization
a) i, ii, and iv only
b) i, ii and iii only
c) ii, iii and iv
only
d) All i, ii, iii,
and iv
View Answer
Answer: b
Explanation: Processing is not the a utility in dbms.
10. ____________
allows individual row operation to be performed on a given result set or on the
generated by a selected by a selected statement.
a) Procedure
b) Trigger
c) Curser
d) None of the
Mentioned
View Answer
Answer: c
Explanation: Triggers are used to initiate a action to
take place.
1. Which s essential
a business problem not a data problem:
a) Data
b) Database
c) Database design
d) All of the
mentioned
View Answer
Answer: c
Explanation: SQL-99 is the most recent version of
standard SQL prescribed by the ANSI.
2. Which is primarily
the result of a thorough understanding of information about an enterprise:
a) Data
b) Database
c) Database design
d) Data modeling
View Answer
Answer: d
Explanation: Data modelling designs the data in a secured
manner.
3. McFadden has
defined normalization in his which book___________
a) Database modern
management
b) Management
database of modern
c) Modern database
management
d) Database
management
View Answer
Answer: c
Explanation: SQL-99 is the most recent version of
standard SQL prescribed by the ANSI.
4. The database
design prevents some data from being represented due to _______
a) Deletion anomalies
b) Insertion
anomalies
c) Update anomaly
d) None of the
mentioned
View Answer
Answer: b
Explanation: Insertion anomaly is due to confusion in
data deletion or insertion.
5. How many types of
insertion anomalies:
a) 1
b) 2
c) 3
d) 4
View Answer
Answer: b
Explanation: Insertion anomaly is due to confusion in
data deletion or insertion.
6. Who developed the
normalization process:
a) E.F. codd
b) F.F. codd
c) E.E. codd
d) None of the mentioned
View Answer
Answer: a
Explanation: Normalization helps in improving the quality
of the data.
7. E.F.Codd developed
the normalization process in the which early:
a) 1969
b) 1970
c) 1971
d) 1972
View Answer
Answer: b
Explanation: Normalization helps in improving the quality
of the data.
8. 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
View Answer
Answer: c
Explanation: Normalization helps in improving the quality
of the data.
9. Which is the
process of breaking a relation into multiple relations:
a) Functional
dependency
b) Database modeling
c) Normalization
d) Decomposition
View Answer
Answer: d
Explanation: SQL-99 is the most recent version of
standard SQL prescribed by the ANSI.
10. Which formal
method that locates and analyses relation schemas on the basis of their
primary, candidate keys, and the FD’s that are present among the attributes of
these schemas:
a) Functional
dependency
b) Database modeling
c) Normalization
d) Decomposition
View Answer
Answer: c
Explanation: Normalization helps in improving the quality
of the data.
1. Which is refers to
a stalemate situation due to which no further progress is possible as computer
await response of each other:
a) Concurrency
b) Deadlock
c) Backup
d) Recovery
View Answer
Answer: b
Explanation: Deadlock will stop further processing.
2. Which is a
duplicate copy of a file program that is stored on a different storage media
than the original location:
a) Concurrency
b) Deadlock
c) Backup
d) Recovery
View Answer
Answer: c
Explanation: Backup is required to take all the data.
3. Which is
duplication of computer operations and routine backups to combat any unforeseen
problems:
a) Concurrency
b) Deadlock
c) Backup
d) Recovery
View Answer
Answer: d
Explanation: Recovery means to take the backup data while
there is a crash.
4. Optimization that
is basically related to the rewriter module is termed as__________
a) Semantic query
optimization
b) Global query
optimization
c) All of the
Mentioned
d) None of the
Mentioned
View Answer
Answer: a
Explanation: SQL-99 is the most recent version of
standard SQL prescribed by the ANSI.
5. Optimization
basically related to the Rewrite module is termed as_______
a) Semantic query
optimization
b) Global query
optimization
c) All of the
Mentioned
d) None of the
Mentioned
View Answer
Answer: a
Explanation: SQL-99 is the most recent version of
standard SQL prescribed by the ANSI.
6. Database security
helps organizations to protect data from _____
a) Internal users
b) External users
c) Non-external users
d) Non internal users
View Answer
Answer: b
Explanation: External users are the people who do not
involve in the processing of the database.
7. Copying files to
secondary or specific devices is known as ______
a) Retrieve
b) Backup
c) Recovery
d) Deadlock
View Answer
Answer: b
Explanation: Backup is required to take all the data.
8. How many types of
recovery control techniques:
a) 2
b) 3
c) 4
d) 5
View Answer
Answer: a
Explanation: Recovery means to take the backup data while
there is a crash.
9. Which are types of
recovery control techniques:
a) Deferred update
b) Immediate update
c) All of the
Mentioned
d) None of the
Mentioned
View Answer
Answer: c
Explanation: Recovery means to take the backup data while
there is a crash.
10. Which server can
joins the indexes when only multiple indexes combined can cover the query:
a) SQL
b) DBMS
c) RDBMS
d) All of the
mentioned
View Answer
Answer: a
Explanation: Indexing reduces the difficulty in searching
the data.
1. In concurrency
control policy the the lock is obtained on
a) Entire database
b) A particular
transaction alone
c) All the new
elements
d) All of the
mentioned
View Answer
Answer: a
Explanation: It is to avoid deadlock.
2. A
concurrency-control policy such as this one leads to ______ performance, since
it forces transactions to wait for preceding transactions to finish before they
can start.
a) Good
b) Average
c) Poor
d) Unstable
View Answer
Answer: c
Explanation: It provides a poor degree of concurrency.
3. __________ are
used to ensure that transactions access each data item in order of the
transactions’ ____ if their accesses conflict.
a) Zone
b) Relay
c) Line
d) Timestamps
View Answer
Answer: d
Explanation: When this is not possible, offending
transactions are aborted and restarted with a new timestamp.
4. EMPDET is an
external table containing the columns EMPNO and ENAME. Which command would work
in relation to the EMPDET table?
a) UPDATE empdet
SET ename = 'Amit'
WHERE empno = 1234;
b) DELETE FROM empdet
WHERE ename LIKE
'J%';
c) CREATE VIEW empvu
AS
SELECT * FROM empdept;
d) CREATE INDEX
empdet_idx
ON empdet(empno);
View Answer
Answer: c
Explanation: View is the temporary space created for the
database.
5. In which scenario
would you use the ROLLUP operator for expression or columns within a GROUP BY
clause?
a) To find the groups
forming the subtotal in a row
b) To create
group-wise grand totals for the groups specified within a GROUP BY clause
c) To create a
grouping for expressions or columns specified within a GROUP BY clause in one
direction, from right to left for calculating the subtotals
d) To create a
grouping for expressions or columns specified within a GROUP BY clause in all
possible directions, which is cross-tabular report for calculating the
subtotals
View Answer
Answer: c
Explanation: View is the temporary space created for the
database.
6.
Name Null? Type
Cust_id Not null Number(2)
Cust_Name Varchar2(15)
Evaluate the
following SQL statements executed in the given order:
ALTER TABLE cust
ADD CONSTRAINT
cust_id_pk PRIMARY KEY(cust_id) DEFERRABLE INITIALLY DEFERRED; INSERT
INTO cust VALUES
(1,'RAJ'); --row 1
INSERT INTO cust
VALUES (1,'SAM'); --row 2
COMMIT;
SET CONSTRAINT
cust_id_pk IMMEDIATE;
INSERT INTO cust
VALUES (1,'LATA'); --row 3
INSERT INTO cust
VALUES (2,'KING'); --row 4
COMMIT;
Which rows would be
made permanent in the CUST table?
a) row 4 only
b) rows 2 and 4
c) rows 3 and 4
d) rows 1 and 4
View Answer
Answer: c
Explanation: View is the temporary space created for the
database.
7. Which statement is
true regarding external tables?
a) The default REJECT
LIMIT for external tables is UNLIMITED
b) The data and
metadata for an external table are stored outside the database
c) ORACLE_LOADER and
ORACLE_DATAPUMP have exactly the same functionality when used with an external
table
d) The CREATE TABLE
AS SELECT statement can be used to unload data into regular table in the
database from an external table
View Answer
Answer: d
Explanation: This will replicate the table as in the
select statement.
8. A non-correlated
subquery can be defined as ______
a) A set of
sequential queries, all of which must always return a single value
b) A set of
sequential queries, all of which must return values from the same table
c) A SELECT statement
that can be embedded in a clause of another SELECT statement only
d) A set of one or
more sequential queries in which generally the result of the inner query is
used as the search value in the outer query
View Answer
Answer: d
Explanation: This will replicate the table as in the
select statement.
9. Evaluate the
following SQL statements in the given order:
DROP TABLE dept;
CREATE TABLE dept
(deptno NUMBER(3)
PRIMARY KEY,
deptname
VARCHAR2(10));
DROP TABLE dept;
FLASHBACK TABLE dept
TO BEFORE DROP;
Which statement is
true regarding the above FLASHBACK operation?
a) It recovers only
the first DEPT table
b) It recovers only
the second DEPT table
c) It does not
recover any of the tables because FLASHBACK is not possible in this case
d) It recovers both
the tables but the names would be changed to the ones assigned in the RECYCLEBIN
View Answer
Answer: b
Explanation: This will replicate the table as in the
select statement.
10.
CREATE TABLE digits
(id NUMBER(2),
description
VARCHAR2(15));
INSERT INTO digits
VALUES (1,'ONE');
UPDATE digits SET
description ='TWO' WHERE id=1;
INSERT INTO digits
VALUES (2,'TWO');
COMMIT;
DELETE FROM digits;
SELECT description
FROM digits
VERSIONS BETWEEN
TIMESTAMP MINVALUE AND MAXVALUE;
What would be the
outcome of the above query?
a) It would not
display any values
b) It would display
the value TWO once
c) It would display
the value TWO twice
d) It would display
the values ONE, TWO, and TWO
View Answer
Answer: c
Explanation: This will replicate the table as in the
select statement.
1. Which of the
following is not a property of transactions?
a) Atomicity
b) Concurrency
c) Isolation
d) Durability
View Answer
Answer: d
Explanation: ACID properties are the properties of
transactions.
2. SNAPSHOT is used
for (DBA)
a) Synonym
b) Tablespace
c) System server
d) Dynamic data
replication
View Answer
Answer: d
Explanation: Snapshot gets the instance of the database
at that time.
3. Isolation of the
transactions is ensured by
a) Transaction
management
b) Application
programmer
c) Concurrency
control
d) Recovery
management
View Answer
Answer: c
Explanation: ACID properties are the properties of
transactions.
4. Constraint
checking can be disabled in existing _______________ and _____________
constraints so that any data you modify or add to the table is not checked
against the constraint.
a) CHECK, FOREIGN KEY
b) DELETE, FOREIGN
KEY
c) CHECK, PRIMARY KEY
d) PRIMARY KEY,
FOREIGN KEY
View Answer
Answer: a
Explanation: Check and foreign constraints are used to
constraint the table data.
5. Problems occurs if
we don’t implement proper locking strategy
a) Dirty reads
b) Phantom reads
c) Lost updates
d) Unrepeatable reads
View Answer
Answer: d
Explanation: In a concurrent execution of these
transactions, it is intuitively clear that they conflict, but this is a
conflict not captured by our simple model. This situation is referred to as the
phantom phenomenon, because a conflict may exist on “phantom” data.
6. Which of the
following fixed database roles can add or remove user IDs?
a) db_accessadmin
b) db_securityadmin
c) db_setupadmin
d) db_sysadmin
View Answer
Answer: a
Explanation: The database can be accessed by assigning
the roles.
7. By default sql
server has ___________ isolation level
a) READ COMMITTED
b) READ UNCOMMITTED
c) SERIALIZABLE
d) REPEATABLE READ
View Answer
Answer: a
Explanation: Read committed is used to commit the default
read operation.
8. Which of the
following statements is/are not true for SQL profiler?
a) Enables you to
monitor events
b) Check if rows are
being inserted properly
c) Check the
performance of a stored procedure
d) ALL of the
mentioned
View Answer
Answer: c
Explanation: Read committed is used to commit the default
read operation.
9. Which of the
following is the original purpose of SQL?
a) To specify the
syntax and semantics of SQL data definition language
b) To specify the
syntax and semantics of SQL manipulation language
c) To define the data
structures
d) All of the
mentioned
View Answer
Answer: d
Explanation: Read committed is used to commit the default
read operation.
10. SQL can be used
to:
a) Create database
structures only
b) Query database
data only
c) Modify database
data only
d) All of the
mentioned
View Answer
Answer: d
Explanation: In a concurrent execution of these
transactions, it is intuitively clear that they conflict, but this is a conflict
not captured by our simple model. This situation is referred to as the phantom
phenomenon, because a conflict may exist on “phantom” data.
1. In order to
maintain transactional integrity and database consistency, what technology does
a DBMS deploy?
a) Triggers
b) Pointers
c) Locks
d) Cursors
View Answer
Answer: c
Explanation: Locks are used to maintain database
consistency.
2. A lock that allows
concurrent transactions to access different rows of the same table is known as
a
a) Database-level
lock
b) Table-level lock
c) Page-level lock
d) Row-level lock
View Answer
Answer: d
Explanation: Locks are used to maintain database
consistency.
3. Which of the
following are introduced to reduce the overheads caused by the log-based
recovery?
a) Checkpoints
b) Indices
c) Deadlocks
d) Locks
View Answer
Answer: d
Explanation: Checkpoints are introduced to reduce
overheads caused by the log-based recovery.
4. Which of the
following protocols ensures conflict serializability and safety from deadlocks?
a) Two-phase locking
protocol
b) Time-stamp
ordering protocol
c) Graph based
protocol
d) None of the
mentioned
View Answer
Answer: b
Explanation: Time-stamp ordering protocol ensures
conflict serializability and safety from deadlocks.
5. Which of the
following is the block that is not permitted to be written back to the disk?
a) Dead code
b) Read only
c) Pinned
d) Zapped
View Answer
Answer: c
Explanation: A block that is not permitted to be written
back to the disk is called pinned.
6. If transaction Ti
gets an explicit lock on the file Fc in exclusive mode, then it has an __________
on all the records belonging to that file.
a) Explicit lock in
exclusive mode
b) Implicit lock in
shared mode
c) Explicit lock in
shared mode
d) Implicit lock in
exclusive mode
View Answer
Answer: d
Explanation: If transaction Ti gets an explicit lock on
the file Fc in exclusive mode, then it has an implicit lock in exclusive mode
on all the records belonging to that file.
7. Which refers to a
property of computer to run several operation simultaneously and possible as
computers await response of each other
a) Concurrency
b) Deadlock
c) Backup
d) Recovery
View Answer
Answer: a
Explanation: Concurrency is a property of systems in
which several computations are executing simultaneously, and potentially
interacting with each other.
8. All lock
information is managed by a __________ which is responsible for assigning and
policing the locks used by the transactions.
a) Scheduler
b) DBMS
c) Lock manager
d) Locking agent
View Answer
Answer: c
Explanation: A distributed lock manager (DLM) provides
distributed software applications with a means to synchronize their accesses to
shared resources.
9. The ____ lock
allows concurrent transactions to access the same row as long as they require
the use of different fields within that row.
a) Table-level
b) Page-level
c) Row-level
d) Field-level
View Answer
Answer: d
Explanation: Lock is limited to the attributes of the
relation.
10. Which of the
following is a procedure for acquiring the necessary locks for a transaction
where all necessary locks are acquired before any are released?
a) Record controller
b) Exclusive lock
c) Authorization rule
d) Two phase lock
View Answer
Answer: d
Explanation: Two-phase lock is a procedure for acquiring
the necessary locks for a transaction where all necessary locks are acquired
before any are released.
1. A system is in a
______ state if there exists a set of transactions such that every transaction
in the set is waiting for another transaction in the set.
a) Idle
b) Waiting
c) Deadlock
d) Ready
View Answer
Answer: c
Explanation: When one data item is waiting for another
data item in a transaction then system is in deadlock.
2. The deadlock state
can be changed back to stable state by using _____________ statement.
a) Commit
b) Rollback
c) Savepoint
d) Deadlock
View Answer
Answer: b
Explanation: Rollback is used to rollback to the point
before lock is obtained.
3. What are the ways
of dealing with deadlock ?
a) Deadlock prevention
b) Deadlock recovery
c) Deadlock detection
d) All of the
mentioned
View Answer
Answer: d
Explanation: Deadlock prevention is also called as
deadlock recovery.Prevention is commonly used if the probability that the
system would enter a deadlock state is relatively high; otherwise, detection
and recovery are more efficient.
4. When transaction
Ti requests a data item currently held by Tj , Ti is allowed to wait only if it
has a timestamp smaller than that of Tj (that is, Ti is older than Tj ).
Otherwise, Ti is rolled back (dies). This is
a) Wait-die
b) Wait-wound
c) Wound-wait
d) Wait
View Answer
Answer: a
Explanation: The wait–die scheme is a non-preemptive
technique.
5. When transaction
Ti requests a data item currently held by Tj , Ti is allowed to wait only if it
has a timestamp larger than that of Tj (that is, Ti is younger than Tj ).
Otherwise, Tj is rolled back (Tj is wounded by Ti ). This is
a) Wait-die
b) Wait-wound
c) Wound-wait
d) Wait
View Answer
Answer: c
Explanation: The wound–wait scheme is a preemptive
technique. It is a counterpart to the wait–die scheme.
6. The situation
where the lock waits only for a specified amount of time for another lock to be
released is
a) Lock timeout
b) Wait-wound
c) Timeout
d) Wait
View Answer
Answer: a
Explanation: The timeout scheme is particularly easy to
implement, and works well if transactions are short and if longwaits are likely
to be due to deadlocks.
7. The deadlock in a
set of transaction can be determined by
a) Read-only graph
b) Wait graph
c) Wait-for graph
d) All of the
mentioned
View Answer
Answer: a
Explanation: Each transaction involved in the cycle is
said to be deadlocked.
8. A deadlock exists
in the system if and only if the wait-for graph contains a ___________
a) Cycle
b) Direction
c) Bi-direction
d) Rotation
View Answer
Answer: a
Explanation: Each transaction involved in the cycle is
said to be deadlocked.
9. Selecting the
victim to be rollbacked to the previous state is determined by the minimum
cost. The factors determining cost of rollback is
a) How long the
transaction has computed, and how much longer the transaction will compute
before it completes its designated task
b) How many data
items the transaction has used
c) How many more data
items the transaction needs for it to complete
d) All of the
mentioned
View Answer
Answer: d
Explanation: We should roll back those transactions that
will incur the minimum cost.
10. __________
rollback requires the system to maintain additional information about the state
of all the running transactions.
a) Total
b) Partial
c) Time
d) Commit
View Answer
Answer: b
Explanation: In total rollback abort the transaction and
then restart it.
1. In a granularity
hierarchy the highest level represents the
a) Entire database
b) Area
c) File
d) Record
View Answer
Answer: a
Explanation: This level is the root of the tree.
2. In a database the
file is contained in ________
a) Entire database
b) Two area
c) One area
d) more than one area
View Answer
Answer: c
Explanation: This level is below the root of the tree.
3. If a node is
locked in an intention mode, explicit locking is done at a lower level of the
tree. This is called
a) Intention lock
modes
b) Explicit lock
c) Implicit lock
d) Exclusive lock
View Answer
Answer: a
Explanation: There is an intention mode associated with
shared mode, and there is one with exclusive mode.
4. If a node is
locked in __________ explicit locking is being done at a lower level of the
tree, but with only shared-mode locks.
a) Intention lock
modes
b) Intention-shared-exclusive
mode
c)
Intention-exclusive (IX) mode
d) Intention-shared
(IS) mode
View Answer
Answer: a
Explanation: There is an intention mode associated with
shared mode, and there is one with exclusive mode.
5. If a node is
locked in ____________ then explicit locking is being done at a lower level,
with exclusive-mode or shared-mode locks.
a) Intention lock
modes
b)
Intention-shared-exclusive mode
c)
Intention-exclusive (IX) mode
d) Intention-shared
(IS) mode
View Answer
Answer: c
Explanation: There is an intention mode associated with
shared mode, and there is one with exclusive mode.
6. If a node is
locked in ______________ the subtree rooted by that node is locked explicitly
in shared mode, and that explicit locking is being done at a lower level with
exclusive-mode locks.
a) Intention lock
modes
b) shared and
intention-exclusive (SIX) mode
c)
Intention-exclusive (IX) mode
d) Intention-shared
(IS) mode
View Answer
Answer: b
Explanation: There is an intention mode associated with
shared mode, and there is one with exclusive mode.
7. ____________
denotes the largest timestamp of any transaction that executed write(Q)
successfully.
a) W-timestamp(Q)
b) R-timestamp(Q)
c) RW-timestamp(Q)
d) WR-timestamp(Q)
View Answer
Answer: a
Explanation: The most common method for doing ordering
transaction is to use a timestamp-ordering scheme.
8. The _____________
ensures that any conflicting read and write operations are executed in
timestamp order.
a) Timestamp-ordering
protocol
b) Timestamp protocol
c) W-timestamp
d) R-timestamp
View Answer
Answer: a
Explanation: The most common method for doing ordering
transaction is to use a timestamp-ordering scheme.
9. The __________
requires that each transaction Ti executes in two or three different phases in
its lifetime, depending on whether it is a read-only or an update transaction.
a) Validation
protocol
b) Validation-based
protocol
c) Timestamp protocol
d) Timestamp-ordering
protocol
View Answer
Answer: a
Explanation: A concurrency-control scheme imposes
overhead of code execution and possible delay of transactions. It may be better
to use an alternative scheme that imposes less overhead.
10. This validation
scheme is called the _________ scheme since transactions execute
optimistically, assuming they will be able to finish execution and validate at
the end.
a) Validation
protocol
b) Validation-based
protocol
c) Timestamp protocol
d) Optimistic
concurrency-control
View Answer
Answer: a
Explanation: A concurrency-control scheme imposes
overhead of code execution and possible delay of transactions. It may be better
to use an alternative scheme that imposes less overhead.
1. The most recent
version of standard SQL prescribed by the American National Standards Institute
is
a) SQL 2011
b) SQL 2002
c) SQL – 4
d) SQL2
View Answer
Answer: a
Explanation: SQL-99 is the most recent version of
standard SQL prescribed by the ANSI.
2. ANSI-standard SQL
allows the use of special operators in conjunction with the WHERE clause. A
special operator used to check whether an attribute value is null is
a) BETWEEN
b) IS NULL
c) LIKE
d) IN
View Answer
Answer: b
Explanation: Exists is used to check whether an attribute
value is null or not in conjunction with the where clause.
3. A lock that
prevents the use of any tables in the database from one transaction while
another transaction is being processed is called a
a) Database-level
lock
b) Table-level lock
c) Page-level lock
d) Row-level lock
View Answer
Answer: a
Explanation: Data base-level lock prevents the use of any
tables in the data base from one transaction while other transaction is being
processed.
4. A condition that
occurs when two transactions wait for each other to unlock data is known as
a(n)
a) Shared lock
b) Exclusive lock
c) Binary lock
d) Deadlock
View Answer
Answer: a
Explanation: Deadlock occurs when two transactions wait
for each other to unlock data.
5. _______ means that
data used during the execution of a transaction cannot be used by a second
transaction until the first one is completed.
a) Serializability
b) Atomicity
c) Isolation
d) Time stamping
View Answer
Answer: c
Explanation: Isolation means that data used during the
execution of a transaction can’t be used by a second transaction until the
first one is completed..
6. A unit of storage
that can store one or more records in a hash file organization is denoted as
a) Buckets
b) Disk pages
c) Blocks
d) Nodes
View Answer
Answer: a
Explanation: Buckets are used to store one or more
records in a hash file organization.
7. The file
organization which allows us to read records that would satisfy the join
condition by using one block read is
a) Heap file
organization
b) Sequential file
organization
c) Clustering file
organization
d) Hash files
organization
View Answer
Answer: c
Explanation: Clustering file organization allows us to
read records that would satisfy the join condition by using one block read.
8. Which of the
following is not true about B+ trees?
a) B+ tree index
takes the form of balanced tree
b) Performance of B+
tree degrades as the file grows
c) Look-up in B+ tree
is straightforward and efficient
d) Insertion and deletion
in B+ tree is complicated but efficient
View Answer
Answer: b
Explanation: The answer is evident .
9. The extent of the
database resource that is included with each lock is called the level of
a) Impact
b) Granularity
c) Management
d) DBMS control
View Answer
Answer: b
Explanation: The extent of the data base resource that is
included with each lock is called the level of Granularity.
10. DBMS periodically
suspends all processing and synchronizes its files and journals through the use
of
a) Checkpoint
facility
b) Backup facility
c) Recovery manager
d) Database change
log
View Answer
Answer: a
Explanation: DBMS periodically suspends all processing
and synchronizes its files and journals though the use of Check point facility.
1. Snapshot isolation
is a particular type of ______________ scheme.
a)
Concurrency-control
b)
Concurrency-allowance
c) Redirection
d)
Repetition-allowance
View Answer
Answer: a
Explanation: It has gained wide acceptance in commercial
and open-source systems, including Oracle, PostgreSQL, and SQL Server.
2. Snapshot isolation
is used to give
a) Transaction a
snapshot of the database
b) Database a
snapshot of the transaction
c) Database a snapshot
of committed values in the transaction
d) Transaction a
snapshot of the database and Database a snapshot of committed values in the
transaction
View Answer
Answer: d
Explanation: The data values in the snapshot consist only
of values written by committed transactions.
3. Lost update
problem is
a) Second update
overwrites the first
b) First update
overwrites the second
c) The updates are
lost due to conflicting problem
d) None of the
mentioned
View Answer
Answer: a
Explanation: Lost update problem has to be resolved.
4. Under first
updater wins the system uses a __________ mechanism that applies only to
updates.
a) Close
b) Read
c) Locking
d) Beat
View Answer
Answer: c
Explanation: Reads are unaffected by this, since they do
not obtain locks.
5. When a transaction
Ti attempts to update a data item, it requests a _________ on that data item.
a) Read lock
b) Update lock
c) Write lock
d) Chain lock
View Answer
Answer: c
Explanation: Reads are unaffected by this, since they do
not obtain locks.
6. Each of a pair of
transactions has read data that is written by the other, but there is no data
written by both transactions, is referred to as
a) Read skew
b) Update skew
c) Write lock
d) None of the
mentioned
View Answer
Answer: d
Explanation: Write skew is the issue addressed here.
7. An application
developer can guard against certain snapshot anomalies by appending a ______
clause to the SQL select query.
a) For update
b) For read
c) For write
d) None of the
mentioned
View Answer
Answer: a
Explanation: Adding the for update clause causes the
system to treat data that are read as if they had been updated for purposes of
concurrency control.
8. Evaluate the
CREATE TABLE statement:
CREATE TABLE products
(product_id NUMBER(6)
CONSTRAINT prod_id_pk PRIMARY KEY, product_name VARCHAR2(15));
Which statement is
true regarding the PROD_ID_PK constraint?
a) It would be
created only if a unique index is manually created first
b) It would be
created and would use an automatically created unique index
c) It would be
created and would use an automatically created no unique index
d) It would be
created and remains in a disabled state because no index is specified in the
command
View Answer
Answer: b
Explanation: Syntax: create table table_name(name
constraint).
9. Evaluate the
following CREATE SEQUENCE statement:
CREATE SEQUENCE seq1
START WITH 100
INCREMENT BY 10
MAXVALUE 200
CYCLE
NOCACHE;
The sequence SEQ1 has
generated numbers up to the maximum limit of 200. You issue the following SQL
statement:
SELECT seq1.nextval
FROM dual;
What is displayed by
the SELECT statement?
a) 1
b) 10
c) 100
d) an error
View Answer
Answer: a
Explanation: Sequence is used to generate a series of
values.
10. In which scenario
would you use the ROLLUP operator for expression or columns within a GROUP BY
clause?
a) To find the groups
forming the subtotal in a row
b) To create
group-wise grand totals for the groups specified within a GROUP BY clause
c) To create a grouping
for expressions or columns specified within a GROUP BY clause in one direction,
from
right to left for
calculating the subtotals
d) To create a
grouping for expressions or columns specified within a GROUP BY clause in all
possible
directions, which is
cross-tabular report for calculating the subtotals
View Answer
Answer: c
Explanation: Sequence is used to generate a series of
values.
1. Which statements
are correct regarding indexes?
a) When a table is
dropped, the corresponding indexes are automatically dropped
b) For each DML
operation performed, the corresponding indexes are automatically updated
c) A non-deferrable
PRIMARY KEY or UNIQUE KEY constraint in a table automatically creates a unique
index
d) All of the
mentioned
View Answer
Answer: d
Explanation: Indexes are used to access the data
efficiently.
2. You executed the
following SQL statements in the given order:
CREATE TABLE orders
(order_id NUMBER(3)
PRIMARY KEY,
order_date DATE,
customer_idnumber(3));
INSERT INTO orders
VALUES (100,'10-mar-2007,,222);
ALTER TABLE orders
MODIFY order_date NOT NULL;
UPDATE orders SET
customer_id=333;
DELETE FROM order;
The DELETE statement
results in the following error:
ERROR at line 1:
table or view does not exist
What would be the
outcome?
a) All the statements
before the DELETE statement would be rolled back
b) All the statements
before the DELETE statement would be implicitly committed within the session
c) All the statements
up to the ALTER TABLE statement would be committed and the outcome of UPDATE
statement would be rolled back
d) All the statements
up to the ALTER TABLE statement would be committed and the outcome of the
UPDATE statement is retained uncommitted within the session
View Answer
Answer: d
Explanation: Committing a transaction refers to making
the changes to record in the database.
3. Evaluate the
following statements:
CREATE TABLE digits
(id NUMBER(2),
description
VARCHAR2(15));
INSERT INTO digits
VALUES (1,'ONE);
UPDATE digits SET
description ='TWO'WHERE id=1;
INSERT INTO digits
VALUES (2 ,'TWO');
COMMIT;
DELETE FROM digits;
SELECT description
FROM digits
VERSIONS BETWEEN
TIMESTAMP MINVALUE AND MAXVALUE;
What would be the
outcome of the above query?
a) It would not
display any values
b) It would display
the value TWO once
c) It would display
the value TWO twice
d) It would display
the values ONE, TWO, and TWO
View Answer
Answer: c
Explanation: The VERSIONS BETWEEN clause of the SELECT
statement is used to create a Flashback Version Query.
4. A non-correlated
subquery can be defined as________
a) A set of
sequential queries, all of which must always return a single value
b) A set of
sequential queries, all of which must return values from the same table
c) A SELECT statement
that can be embedded in a clause of another SELECT statement only
d) A set of one or
more sequential queries in which generally the result of the inner query is
used as the search value in the outer query
View Answer
Answer: d
Explanation: A noncorrelated subquery is subquery that is
independent of the outer query and it can executed on its own without relying
on main outer query.
5. Which statement is
true regarding synonyms?
a) Synonyms can be
created for tables but not views
b) Synonyms are used
to reference only those tables that are owned by another user
c) A public synonym
and a private synonym can exist with the same name for the same table
d) The DROP SYNONYM
statement removes the synonym, and the status of the table on which the synonym
has been created becomes invalid
View Answer
Answer: c
Explanation: A synonym is an alias or alternate name for
a table, view, sequence, or other schema object. They are used mainly to make
it easy for users to access database objects owned by other users.
6. SCOTT is a user in
the database.
Evaluate the commands
issued BY the DBA:
1 - CREATE ROLE mgr;
2 - GRANT CREATE
TABLE, SELECT
ON oe. orders TO mgr;
3 - GRANT mgr, CREATE
TABLE TO SCOTT;
Which statement is
true regarding the execution of the above commands?
a) Statement 1 would
not execute because the WITH GRANT option is missing
b) Statement 1 would
not execute because the IDENTIFIED BY clause is missing
c) Statement 3 would
not execute because role and system privileges cannot be granted together in a
single GRANT statement
d) Statement 2 would
not execute because system privileges and object privileges cannot be granted
together in a single GRANT command
View Answer
Answer: d
Explanation: The GRANT statement is used to give
privileges to a specific user or role, or to all users, to perform actions on
database objects.
7. OE and SCOTT are
the users in the database. The ORDERS table is owned by OE. Evaluate the
statements issued by the DBA in the following sequence:
CREATE ROLE r1;
GRANT SELECT, INSERT
ON oe. orders TO r1;
GRANT r1 TO scott;
GRANT SELECT ON oe.
orders TO scott;
REVOKE SELECT ON
oe.orders FROM scott;
What would be the
outcome after executing the statements?
a) SCOTT would be
able to query the OE.ORDERS table
b) SCOTT would not be
able to query the OE.ORDERS table
c) The REVOKE
statement would remove the SELECT privilege from SCOTT as well as from the role
R1
d) The REVOKE
statement would give an error because the SELECT privilege has been granted to
the role R1
View Answer
Answer: a
Explanation: The REVOKE statement is used to remove
privileges from a specific user or role, or from all users, to perform actions
on database objects.
8. Given below are
the SQL statements executed in a user session:
CREATE TABLE product
(pcode NUMBER(2),
pnameVARCHAR2(10));
INSERT INTO product
VALUES(1, 'pen');
INSERT INTO product
VALUES (2,'penci');
SAVEPOINT a;
UPDATE product SET
pcode = 10 WHERE pcode = 1;
SAVEPOINT b;
DELETE FROM product
WHERE pcode = 2;
COMMIT;
DELETE FROM product
WHERE pcode=10;
ROLLBACK TO SAVEPOINT
a;
Which statement describes
the consequences?
a) No SQL statement
would be rolled back
b) Both the DELETE
statements would be rolled back
c) Only the second
DELETE statement would be rolled back
d) Both the DELETE
statements and the UPDATE statement would be rolled back
View Answer
Answer: d
Explanation: The SAVEPOINT statement names and marks the
current point in the processing of a transaction. With the ROLLBACK TO
statement, savepoints undo parts of a transaction instead of the whole
transaction.
9. Evaluate the
following command:
CREATE TABLE
employees (employee_id NUMBER(2) PRIMARY KEY, last_name VARCHAR2(25) NOT
NULL, department_id
NUMBER(2), job_id VARCHAR2(8), salary NUMBER(10,2));
You issue the
following command TO CREATE a VIEW that displays the IDs AND LAST names OF the
sales staff IN the organization:
CREATE OR REPLACE
VIEW sales_staff_vu AS SELECT employee_id, last_name job_id FROM employees
WHERE job_id LIKE
'SA_%' WITH CHECK OPTION;
Which statements are
true regarding the above view?
a) It allows you to
insert details of all new staff into the EMPLOYEES table
b) It allows you to
delete the details of the existing sales staff from the EMPLOYEES table
c) It allows you to
update the job ids of the existing sales staff to any other job id in the
EMPLOYEES table
d) It allows you to
insert the IDs, last
View Answer
Answer: d
Explanation: SQL Create view syntax :
CREATE VIEW view_name
AS
SELECT column_name(s)
FROM TABLE_NAME
WHERE condition.
10. EMPDET is an
external table containing the columns EMPNO and ENAME. Which command would work
in relation to the EMPDET table?
a) UPDATE empdet
SET ename = 'Amit'
WHERE empno = 1234;
b) DELETE FROM empdet
WHERE ename LIKE
'J%';
c) CREATE VIEW empvu
AS
SELECT* FROM empdept;
d) CREATE INDEX
empdet_idx
ON empdet(empno);
View Answer
Answer: c
Explanation: External tables are created using the SQL
CREATE TABLE…ORGANIZATION EXTERNAL statement. When an external table is
created, you specify type ,default directory, access parameters and location.
1. The method of
access that uses key transformation is called as
a) Direct
b) Hash
c) Random
d) Sequential
View Answer
Answer: b
Explanation: Hash technique uses particular hash key
value.
2. Why do we need
concurrency control on B+ trees ?
a) To remove the
unwanted data
b) To easily add the
index elements
c) To maintain
accuracy of index
d) All of the
mentioned
View Answer
Answer: c
Explanation: Indices do not have to be treated like other
database structures.
3. How many
techniques are available to control concurrency on B+ trees?
a) One
b) Three
c) Four
d) None of the
mentioned
View Answer
Answer: d
Explanation: Two techniques are present.
4. In crabbing
protocol locking
a) Goes down the tree
and back up
b) Goes up the tree
and back down
c) Goes down the tree
and releases
d) Goes up the tree
and releases
View Answer
Answer: a
Explanation: It moves in a crab like manner.
5. The deadlock can
be handled by
a) Removing the nodes
that are deadlocked
b) Restarting the
search after releasing the lock
c) Restarting the
search without releasing the lock
d) Resuming the
search
View Answer
Answer: b
Explanation: Crabbing protocol moves in a crab like
manner.
6. In crabbing
protocol the the lock obtained on the root node is in _________ mode.
a) Shared
b) Exclusive
c) Read only
d) None of the mentioned
View Answer
Answer: a
Explanation: Crabbing protocol moves in a crab like
manner down the index tree.
7. If needed to split
a node or coalesce it with its siblings, or redistribute key values between
siblings, the crabbing protocol locks the parent of the node in ____________
mode.
a) Shared
b) Exclusive
c) Read only
d) None of the
mentioned
View Answer
Answer: b
Explanation: Crabbing protocol moves in a crab like
manner down the index tree.
8. In crabbing
protocol to inset or delete a key value the leaf node has to be locked in
___________ mode.
a) Shared
b) Exclusive
c) Read only
d) None of the
mentioned
View Answer
Answer: b
Explanation: Crabbing protocol moves in a crab like
manner down the index tree.
9. B-link tree
requires a pointer to its __________ sibling.
a) Upper
b) Lower
c) Right
d) Left
View Answer
Answer: c
Explanation: This pointer is required because a lookup
that occurs while a node is being split may have to search not only that node
but also that node’s right sibling.
10. Instead of
locking index leaf nodes in a two-phase manner, some index concurrency-control
schemes use ___________ on individual key values, allowing other key values to
be inserted or deleted from the same leaf.
a) B+ tree locking
b) Link level locking
c) Key-value locking
d) Next value locking
View Answer
Answer: c
Explanation: Key-value locking thus provides increased
concurrency.
1. The recovery
scheme must also provide
a) High availability
b) Low availability
c) High reliability
d) High durability
View Answer
Answer: a
Explanation: It must minimize the time for which the
database is not usable after a failure.
2. Which one of the
following is a failure to system
a) Boot crash
b) Read failure
c) Transaction
failure
d) All of the
mentioned
View Answer
Answer: c
Explanation: Types of system failure are transaction
failure, system crash and disk failure.
3. Which of the
following belongs to transaction failure
a) Read error
b) Boot error
c) Logical error
d) All of the
mentioned
View Answer
Answer: c
Explanation: Types of system transaction failure are
logical and system error.
4. The system has
entered an undesirable state (for example, deadlock), as a result of which a
transaction cannot continue with its normal execution. This is
a) Read error
b) Boot error
c) Logical error
d) System error
View Answer
Answer: c
Explanation: The transaction, can be re-executed at a
later time.
5. The transaction
can no longer continue with its normal execution because of some internal
condition, such as bad input, data not found, overflow, or resource limit
exceeded. This is
a) Read error
b) Boot error
c) Logical error
d) System error
View Answer
Answer: c
Explanation: The transaction, can be re-executed at a
later time.
6. The assumption
that hardware errors and bugs in the software bring the system to a halt, but
do not corrupt the nonvolatile storage contents, is known as the
a) Stop assumption
b) Fail assumption
c) Halt assumption
d) Fail-stop
assumption
View Answer
Answer: d
Explanation: Well-designed systems have numerous internal
checks, at the hardware and the software level, that bring the system to a halt
when there is an error. Hence, the fail-stop assumption is a reasonable one.
7. Which kind of
failure loses its data in head crash or failure during transfer operation.
a) Transaction
failure
b) System crash
c) Disk failure
d) All of the
mentioned
View Answer
Answer: c
Explanation: Copies of the data on other disks, or
archival backups on tertiary media, such as DVD or tapes, are used to recover
from the failure.
8. The failure
occurred sufficiently early during the transfer that the destination block
remains intact.
a) Partial Failure
b) Total failure
c) Successful
completion
d) Data transfer
failure
View Answer
Answer: a
Explanation: Copies of the data on other disks, or
archival backups on tertiary media, such as DVD or tapes, are used to recover
from the failure.
9. The database is
partitioned into fixed-length storage units called
a) Parts
b) Blocks
c) Reads
d) Build
View Answer
Answer: b
Explanation: Blocks are the units of data transfer to and
from disk, and may contain several data items.
10. Which of the
following causes system to crash
a) Bug in software
b) Loss of volatile
data
c) Hardware
malfunction
d) All of the
mentioned
View Answer
Answer: d
Explanation: The content of non-volatile storage remains
intact, and is not corrupted.
This set of Database
Multiple Choice Questions & Answers (MCQs) focuses on “Recovery”.
1. The log is a
sequence of _________ recording all the update activities in the database.
a) Log records
b) Records
c) Entries
d) Redo
View Answer
Answer: a
Explanation: The most widely used structure for recording
database modifications is the log.
2. In the ___________
scheme, a transaction that wants to update the database first creates a
complete copy of the database.
a) Shadow copy
b) Shadow Paging
c) Update log records
d) All of the
mentioned
View Answer
Answer: a
Explanation: If at any point the transaction has to be
aborted, the system merely deletes the new copy. The old copy of the database
has not been affected.
3. The ____________
scheme uses a page table containing pointers to all pages; the page table
itself and all updated pages are copied to a new location.
a) Shadow copy
b) Shadow Paging
c) Update log records
d) All of the
mentioned
View Answer
Answer: b
Explanation: Any page which is not updated by a
transaction is not copied, but instead the new page table just stores a pointer
to the original page.
4. The current copy
of the database is identified by a pointer, called ____________ which is stored
on disk.
a) Db-pointer
b) Update log
c) Update log records
d) All of the
mentioned
View Answer
Answer: a
Explanation: Any page which is not updated by a
transaction is not copied, but instead the new page table just stores a pointer
to the original page.
5. If a transaction
does not modify the database until it has committed, it is said to use the
___________ technique.
a)
Deferred-modification
b) Late-modification
c)
Immediate-modification
d) Undo
View Answer
Answer: a
Explanation: Deferred modification has the overhead that
transactions need to make local copies of all updated data items; further, if a
transaction reads a data item that it has updated, it must read the value from
its local copy.
6. If database
modifications occur while the transaction is still active, the transaction is
said to use the ___________technique.
a)
Deferred-modification
b) Late-modification
c)
Immediate-modification
d) Undo
View Answer
Answer: c
Explanation: We say a transaction modifies the database
if it performs an update on a disk buffer, or on the disk itself; updates to
the private part of main memory do not count as database modifications.
7. ____________ using
a log record sets the data item specified in the log record to the old value.
a)
Deferred-modification
b) Late-modification
c)
Immediate-modification
d) Undo
View Answer
Answer: d
Explanation: Undo brings the previous contents.
8. In the __________
phase, the system replays updates of all transactions by scanning the log
forward from the last checkpoint.
a) Repeating
b) Redo
c) Replay
d) Undo
View Answer
Answer: b
Explanation: Undo brings the previous contents.
9. The actions which
are played in the order while recording it is called ______________ history.
a) Repeating
b) Redo
c) Replay
d) Undo
View Answer
Answer: a
Explanation: Undo brings the previous contents.
10. A special
redo-only log record <Ti , Xj , V1> is written to the log, where V1 is
the value being restored to data item Xj during the rollback. These log records
are sometimes called
a) Log records
b) Records
c) Compensation log
records
d) Compensation redo
records
View Answer
Answer: c
Explanation: Such records do not need undo information,
since we never need to undo such an undo operation.
This set of Database
Multiple Choice Questions & Answers (MCQs) focuses on “Buffer Management”.
1. In order to reduce
the overhead in retrieving the records from the storage space we use
a) Logs
b) Log buffer
c) Medieval space
d) Lower records
View Answer
Answer: b
Explanation: The output to stable storage is in units of
blocks.
2. The order of log
records in the stable storage ____________ as the order in which they were
written to the log buffer.
a) Must be exactly
the same
b) Can be different
c) Is opposite
d) Can be partially
same
View Answer
Answer: a
Explanation: As a result of log buffering, a log record
may reside in only main memory (volatile storage) for a considerable time
before it is output to stable storage.
3. Before a block of
data in main memory can be output to the database, all log records pertaining
to data in that block must have been output to stable storage. This is
a) Read-write logging
b) Read-ahead logging
c) Write-ahead
logging
d) None of the
mentioned
View Answer
Answer: c
Explanation: The WAL rule requires only that the undo
information in the log has been output to stable storage, and it permits the
redo information to be written later.
4. Writing the
buffered log to __________ is sometimes referred to as a log force.
a) Memory
b) Backup
c) Redo memory
d) Disk
View Answer
Answer: d
Explanation: If there are insufficient log records to
fill the block, all log records in main memory are combined into a partially
full block and are output to stable storage.
5. The
_______________ policy, allows a transaction to commit even if it has modified
some blocks that have not yet been written back to disk.
a) Force
b) No-force
c) Steal
d) No-steal
View Answer
Answer: b
Explanation: No-force policy allows faster commit of
transactions.
6. ______________
policy allows multiple updates to accumulate on a block before it is output to
stable storage, which can reduce the number of output operations greatly for
frequently updated blocks.
a) Force
b) No-force
c) Steal
d) No-steal
View Answer
Answer: b
Explanation: No-force policy allows faster commit of
transactions.
7. The ___________
policy, allows the system to write modified blocks to disk even if the
transactions thatmade those modifications have not all committed.
a) Force
b) No-force
c) Steal
d) No-steal
View Answer
Answer: c
Explanation: The no-steal policy does not work with
transactions that perform a large number of updates.
8. Locks on buffer
blocks are unrelated to locks used for concurrency-control of transactions, and
releasing them in a non-two-phase manner does not have any implications on
transaction serializability. This is
a) Latches
b) Swap Space
c) Dirty Block
d) None of the
mentioned
View Answer
Answer: a
Explanation: These locks, and other similar locks that
are held for a short duration.
9. The
__________________ contains a list of blocks that have been updated in the
database buffer.
a) Latches
b) Swap Space
c) Dirty Block
d) None of the
mentioned
View Answer
Answer: c
Explanation: Dirty blocks are those that have been
updated in memory, and the disk version is not up-to-date.
10. The operating
system reserves space on disk for storing virtual-memory pages that are not
currently in main memory; this space is called
a) Latches
b) Swap Space
c) Dirty Block
d) None of the
mentioned
View Answer
Answer: b
Explanation: Almost all current-generation operating
systems retain complete control of virtual memory.
This set of Database
Multiple Choice Questions & Answers (MCQs) focuses on “Failure with
Nonvolatile Storage”.
1. The silicon chips
used for data processing are called
a) RAM chips
b) ROM chips
c) Micro processors
d) PROM chips
View Answer
Answer: d
Explanation: PROM is Programmable Read Only Memory.
2. Which of the
following is used for manufacturing chips?
a) Control bus
b) Control unit
c) Parity unit
d) Semiconductor
View Answer
Answer: d
Explanation: A semiconductor is a material which has
electrical conductivity between that of a conductor such as copper and that of
an insulator such as glass.
3. What was the name
of the first commercially available microprocessor chip?
a) Intel 308
b) Intel 33
c) Intel 4004
d) Motorola 639
View Answer
Answer: c
Explanation: The Intel 4004 is a 4-bit central processing
unit (CPU) released by Intel Corporation in 1971
4. The magnetic
storage chip used to provide non-volatile direct access storage of data and
that have no moving parts are known as
a) Magnetic core
memory
b) Magnetic tape
memory
c) Magnetic disk
memory
d) Magnetic bubble
memory
View Answer
Answer: d
Explanation: Bubble domain visualization by using
CMOS-MagView.
5. The ALU of a
computer normally contains a number of high speed storage element called
a) Semiconductor
memory
b) Registers
c) Hard disks
d) Magnetic disk
View Answer
Answer: b
Explanation: External control unit tells the ALU what
operation to perform on that data, and then the ALU stores its result into an
output register.
6. Which of the
following is used only for data entry and storage, and never for processing?
a) Mouse
b) Dumb terminal
c) Micro computer
d) Dedicated data
entry system
View Answer
Answer: b
Explanation: Dumb terminals are those that can interpret
a limited number of control codes.
7. Non-volatile
storage needs to have a _________ where the loses in future can be recovered.
a) Dump
b) Recover place
c) Disk
d) Redo plan
View Answer
Answer: a
Explanation: The basic scheme is to dump the entire
contents of the database to stable storage periodically—say, once per day.
8. A dump of the
database contents is also referred to as an _____________ dump.
a) Archival
b) Fuzzy
c) SQL
d) All of the
mentioned
View Answer
Answer: a
Explanation: We can archive the dumps and use them later
to examine old states of the database.
9. ________ dump,
writes out SQL DDL statements and SQL insert statements to a file, which can
then be reexecuted to re-create the database.
a) Archival
b) Fuzzy
c) SQL
d) All of the
mentioned
View Answer
Answer: c
Explanation: Such dumps are useful when migrating data to
a different instance of the database, or to a different version of the database
software, since the physical locations and layout may be different in the other
database instance or database software version.
10. _________ dump
schemes have been developed that allow transactions to be active while the dump
is in progress.
a) Archival
b) Fuzzy
c) SQL
d) All of the
mentioned
View Answer
Answer: b
Explanation: The simple dump procedure described here is
costly and so fuzzy dump is used.
This set of Database
Multiple Choice Questions & Answers (MCQs) focuses on “ARIES”.
1. ARIES uses a
___________ to identify log records, and stores it in database pages.
a) Log sequence
number
b) Log number
c) Lock number
d) Sequence
View Answer
Answer: b
Explanation: LSN to is used identify which operations
have been applied to a database page.
2. ARIES supports
___________ operations, which are physical in that the affected page is
physically identified, but can be logical within the page.
a) Physiological redo
b) Physiological undo
c) Logical redo
d) Logical undo
View Answer
Answer: a
Explanation: The deletion of a record from a page may
result in many other records in the page being shifted, if a slotted page
structure is used.
3. ______________ is
used to minimize unnecessary redos during recovery.
a) Dirty page table
b) Page table
c) Dirty redo
d) All of the
mentioned
View Answer
Answer: a
Explanation: Dirty pages are those that have been updated
in memory, and the disk version is not up-to-date.
4. __________ scheme
that records only information about dirty pages and associated information and
does not even require of writing dirty pages to disk.
a) Fuzzy logic
b) Checkpoints
c) Fuzzy-checkpoint
d) Logical checkpoint
View Answer
Answer: c
Explanation: It flushes dirty pages in the background,
continuously, instead of writing them during checkpoints.
5. Whenever an update
operation occurs on a page, the operation stores the LSN of its log record in
the _______ field of the page.
a) LSN
b) ReadLSN
c) PageLSN
d) RedoLSN
View Answer
Answer: c
Explanation: Each page maintains an identifier called the
PageLSN.
6. There are special
redo-only log records generated during transaction rollback, called _________
in ARIES.
a) Compensation log
records
b) Read log records
c) Page log records
d) Redo log records
View Answer
Answer: a
Explanation: These serve the same purpose as the
redo-only log records in our earlier recovery scheme.
7. The
__________________ contains a list of pages that have been updated in the database
buffer.
a) Dirty page table
b) Page table
c) Dirty redo
d) All of the
mentioned
View Answer
Answer: a
Explanation: Dirty pages are those that have been updated
in memory, and the disk version is not up-to-date.
8. ___________
determines which transactions to undo,which pages were dirty at the time of the
crash, and the LSN from which the redo pass should start.
a) Analysis pass
b) Redo pass
c) Undo pass
d) None of the
mentioned
View Answer
Answer: a
Explanation: The analysis pass finds the last complete
checkpoint log record, and reads in the DirtyPageTable from this record.
9. __________ starts
from a position determined during analysis, and performs a redo, repeating
history, to bring the database to a state it was in before the crash.
a) Analysis pass
b) Redo pass
c) Undo pass
d) None of the
mentioned
View Answer
Answer: b
Explanation: The redo pass repeats history by replaying
every action that is not already reflected in the page on disk.
10. ______________ rolls
back all transactions that were incomplete at the time of crash.
a) Analysis pass
b) Redo pass
c) Undo pass
d) None of the
mentioned
View Answer
Answer: c
Explanation: It performs a single backward scan of the
log, undoing all transactions in undo-list.
This set of Database
Multiple Choice Questions & Answers (MCQs) focuses on “Lock Release and
Undo Operations”.
1. Which lock should
be obtained to prevent a concurrent transaction from executing a conflicting
read, insert or delete operation on the same key value.
a) Higher-level lock
b) Lower-level lock
c) Read only lock
d) Read write
View Answer
Answer: a
Explanation: Operations acquire lower-level locks while
they execute, but release them when they complete; the corresponding
transaction must however retain a higher-level lock in a two-phase manner to
prevent concurrent transactions from executing conflicting actions.
2. Once the
lower-level lock is released, the operation cannot be undone by using the old
values of updated data items, and must instead be undone by executing a
compensating operation; such an operation is called
a) Logical operation
b) Redo operation
c) Logical undo
operation
d) Undo operation
View Answer
Answer: a
Explanation: It is important that the lower-level locks
acquired during an operation are sufficient to perform a subsequent logical
undo of the operation.
3. Which of the
following is used for undo operations alone ?
a) Logical logging
b) Physical logging
c) Physical log
records
d) Physical logging
and Physical log records
View Answer
Answer: a
Explanation: If the operation inserted an entry in a
B+-tree, the undo information U would indicate that a deletion operation is to
be performed, and would identify the B+-tree and what entry to delete from the
tree. Such logging of information about operations is called logical logging.
4. Redo operations
are performed exclusively using
a) Logical logging
b) Physical logging
c) Physical log
records
d) Both Physical
logging and Physical log records
View Answer
Answer: d
Explanation: Logging of old-value and new-value
information is called physical logging.
5. To perform logical
redo or undo, the database state on disk must be operation ___________ that is,
it should not have partial effects of any operation.
a) Persistent
b) Resistant
c) Consistent
d) None of the
mentioned
View Answer
Answer: c
Explanation: Data structures such as B+-trees would not
be in a consistent state, and neither logical redo nor logical undo operations
can be performed on an inconsistent data structure.
6. An operation is
said to be __________ if executing it several times in a row gives the same
result as executing it once.
a) Idempotent
b) Changed
c) Repetitive
d) All of the above
View Answer
Answer: a
Explanation: Operations such as inserting an entry into a
B+-tree may not be idempotent, and the recovery algorithm must therefore make
sure that an operation that has already been performed is not performed again.
7. Immediate database
modification technique uses
a) Both undo and redo
b) Undo but no redo
c) Redo but no undo
d) Neither undo nor
redo
View Answer
Answer: a
Explanation: Undo erases all the changes and redo makes
the deleted changes.
8. Shadow paging has
a) no redo
b) no undo
c) redo but no undo
d) neither redo nor
undo
View Answer
Answer: a
Explanation: Undo erases all the changes and redo makes
the deleted changes.
9. For correct
behaviour during recovery, undo and redo operation must be
a) Commutative
b) Associative
c) Idempotent
d) Distributive
View Answer
Answer: c
Explanation: Undo erases all the changes and redo makes
the deleted changes.
10. If ___________
are not obtained in undo operation it will cause problem in undo-phase.
a) Higher-level lock
b) Lower-level lock
c) Read only lock
d) Read write
View Answer
Answer: b
Explanation: Operations acquire lower-level locks while
they execute, but release them when they complete; the corresponding
transaction must however retain a higher-level lock in a two-phase manner to
prevent concurrent transactions from executing conflicting actions.
This set of Database
Multiple Choice Questions & Answers (MCQs) focuses on “Remote Backup
Systems”.
1. The remote backup
site is sometimes also called the
a) Primary Site
b) Secondary Site
c) Tertiary Site
d) None of the
mentioned
View Answer
Answer: b
Explanation: We can achieve high availability by
performing transaction processing at one site, called the primary site, and
having a remote backup site where all the data from the primary site are
replicated.
2. Remote backup
system must be _________ with the primary site.
a) Synchronised
b) Separated
c) Connected
d) Detached but
related
View Answer
Answer: a
Explanation: We can achieve high availability by
performing transaction processing at one site, called the primary site, and
having a remote backup site where all the data from the primary site are
replicated.
3. The backup is
taken by
a) Erasing all
previous records
b) Entering the new
records
c) Sending all log
records from primary site to the remote backup site
d) Sending selected
records from primary site to the remote backup site
View Answer
Answer: c
Explanation: We can achieve high availability by
performing transaction processing at one site, called the primary site, and
having a remote backup site where all the data from the primary site are
replicated.
4. When the
__________ the backup site takes over processing and becomes the primary.
a) Secondary fails
b) Backup recovers
c) Primary fails
d) None of the
mentioned
View Answer
Answer: c
Explanation: When the original primary site recovers, it
can either play the role of remote backup, or take over the role of primary
site again.
5. The simplest way
of transferring control is for the old primary to receive __________ from the
old backup site.
a) Undo logs
b) Redo Logs
c) Primary Logs
d) All of the
mentioned
View Answer
Answer: c
Explanation: If control must be transferred back, the old
backup site can pretend to have failed, resulting in the old primary taking
over.
6. The time to
process the remote backup can be reduced by
a) Flags
b) Breakpoints
c) Redo points
d) Checkpoints
View Answer
Answer: d
Explanation: If the log at the remote backup grows large,
recovery will take a long time. The remote backup site can periodically process
the redo log records that it has received and can perform a checkpoint, so that
earlier parts of the log can be deleted.
7. A _______________
configuration can make takeover by the backup site almost instantaneous.
a) Hot-spare
b) Remote
c) Direct
d) Spare
View Answer
Answer: d
Explanation: In this configuration, the remote backup
site continually processes redo log records as they arrive, applying the
updates locally.
8. A transaction
commits as soon as its commit log record is written to stable storage at the
primary site. This is
a) One Safe
b) Two Safe
c) Two-very Safe
d) Very Safe
View Answer
Answer: a
Explanation: The problem with this scheme is that the
updates of a committed transaction may not have made it to the backup site,
when the backup site takes over processing.
9. A transaction
commits as soon as its commit log record is written to stable storage at the
primary and the backup site.This is
a) One Safe
b) Two Safe
c) Two-very Safe
d) Very Safe
View Answer
Answer: c
Explanation: The problem with this scheme is that
transaction processing cannot proceed if either the primary or the backup site
is down.
10. If only the
primary is active, the transaction is allowed to commit as soon as its commit
log record is written to stable storage at the primary site. This is
a) One Safe
b) Two Safe
c) Two-very Safe
d) Very Safe
View Answer
Answer: b
Explanation: This scheme provides better availability
than does two-very-safe,while avoiding the problem of lost transactions faced
by the one-safe scheme
