Database locking concept is used to solve the problem of
Lost Update
Uncommitted Dependency
Inconsistent Data
All of the above
Correct Answer :
D. All of the above
Related Questions
What does a field or a combination of fields that has a unique value called ?
Foreign key
Secondary key
Primary key
Alternate key
The exists construct returns the value true, if the argument subquery is
empty
nonempty
contains null values
none of the above
A ………… clause permits a view definition to be used in multiple places within a query.
where
exist
with
select
The raw facts and figures are:
Data
Data field
DBMS
DBASE
Which of the following submit and execute query at run time?
Static SQL
Dynamic SQL
both
none of these
The syntax to select all column from the table is
select all from tablename
select * from tablename
select from tablename
none of these
Which of the following is true statement ?
SQL permits attribute names to be repeated in the same relation.
a SQL query automatically eliminates duplicates.
a SQL query will not work if there are no indexes on the relations
None of these
A DBMS query language is designed to
support end users who use English-like commands.
support in the development of complex applications software.
specify the structure of a database.
all of the above.
Natural mask for a Class A network
255.0.0.0
255.255.0.0
255.255.255.0
none of these
The attribute that can be divided into other attributes is called
Simple Attribute
Composite Attribute
Multi-valued Attribute
Derived Attribute
Cross Product is a:
Unary Operator
Binary Operator
Ternary Operator
none of the above
Commit operation …………… writes the changes made to the database.
temporarily
permanently
none of these
all of the above
What does the number of attributes in a relation is called?
Cardinality
Degree
Tuple
Order
Disk storage is referred to as
sequential access storage
direct access storage
random access storage
none of the above
The control of concurrent execution is left with the
operating system
controller unit of the kernel
concurrency control component of the database system
none
DBMS helps achieve
Data independence
Centralized control of data
Neither A) nor B)
both A) and B)
The command used to delete a particular column in a relation
UPDATE
DROP
ALTER
DELETE
A transaction which completes successfully is called
Granted
Committed
Compensated
Accomplished
Attenuation can be also expressed in decibel dB) and commonly used because.
i) Signal strengths often fall off logarithmically
ii) Cascade losses and gains can be calculated with simple additions and subtractions
i only
ii only
Both A and B
None of the above
Select the correct
i) A timestamp-based scheduler cant produce live lock
ii) Aggregate functions cant appear with HAVING clause.
iii) Isolation is a property of database transaction.
i and ii only
ii and iii only
i and iii only
i only
An entity set that does not have sufficient attributes to form a primary key is a
strong entity set.
weak entity set.
simple entity set.
primary entity set.
Repeaters operate in
i) Physical layer
ii) Datalink layer
iii) Transport layer
iv) Network layer
i and ii only
ii and iii only
ii only
i only
Expand the acronym OLAP
Object Linked Access Program
Organizational Architecture Processing
Online Analytical Processing
none of these
Secondary storage
magnetic disk
magnetic tape
juke box
cache
A logical schema
is the entire database.
is a standard way of organizing information into accessible parts.
describes how data is actually stored on disk.
both A) and C)
Referential integrity
controls relationships between operations of an object
controls relationships between instances of a class
controls relationships between attributes in a table
controls relationships between tables in a database
Which of the following works as a filter?
UPDATE
DROP
ALTER
SELECT
Which topology requires a central controller or hub?
Ring
Tree
Switch
Graph
A logical description of some portion of database that is required by a user to perform task is called as
System View
User View
Logical View
Data View
Radio frequencies below ............. are more suitable for omnidirectional applications.
300MHz
1GHz
5GHz
10 GHz