Which of the following aggregate function doesnt ignore NULLs in its results?
COUNT
COUNT(*)
MAX
none of these
Correct Answer :
B. COUNT(*)
Related Questions
Expand the acronym OLAP
Object Linked Access Program
Organizational Architecture Processing
Online Analytical Processing
none of these
As a side-effect of database update ,the system automatically executes a statement called
a view
a grant permission
a trigger
all of the above
It is possible to define a schema completely using
VDL and DDL.
DDL and DML.
SDL and DDL.
VDL and DML.
Noiseless channel has ……… types of protocols.
2
3
4
5
.................. is the loss of energy as the signal propagates outward, where the amount of energy depends on the frequency.
Noise
Delay distortion
Attenuation distortion
Dispersion
Thermal noise is often referred to as ............... noise, because it affects uniformly the different frequencies.
Gray
White
Blue
Black
Which of the following operator preserves unmatched rows of the relations being joined?
Inner join
Outer join
union
Intersect
The race condition occurs when
Two concurrent processes attempt to interact with each other.
Two concurrent processes interact with different data files.
Two concurrent processes attempt to hold a data item .
none of the above.
RAID
Redundant Arrays of Independent Disks
Redundant Arrays of Independent Drives
Redundant Arrays of Interconnected Drives
Redundant Arrays of Interconnected Disks
DBMS utility which allows to reconstruct the correct state of database from the backup and history of transactions
Backup
Recovery
Grant
Troubleshooting
Tertiary storage
magnetic tape
juke box
optical disk
All of the above
Mail services are available to network users through the
Session layer
Presentation layer
Application layer
Transport layer
Radio frequencies below ............. are more suitable for omnidirectional applications.
300MHz
1GHz
5GHz
10 GHz
File organization that provides fast access to any arbitrary record
Hashed file
B-tree
Ordered file
Unordered file
Which of the following is not a database object?
index
sequence
cursor
trigger
The maximum number of children in a B-tree of order m is
m+1
m
m-1
m/2
FDDI protocol operates in
i) Transport layer
ii) Network layer
iii) Datalink layer
iv) Physical layer
i and ii only
ii and iii only
i and iii only
iii and iv only
In client/server computing data are
sent only upon the client's request
sent in complete copies for the client to filter and sort
never sent to the client machine
sent in very large sections to save processing time
Which of the following layer uses trailer of the frame for error detection?
Transport layer
Network layer
Datalink layer
None of these
EEPROM
Electrically Extractable Programmable Read Only Memory
Electrically Erasable Programmable Read Only Memory
Electronically Erasable Programmable Read Only Memory
Electrically Erasable Programmable Read Only Memory
Which of the following is a classical approach to database design?
Left Right approach
Right Left approach
Top Down approach
Bottom Up approach
An operation that will increase the length of a list is
insert
modify
lookup
none of the above
Three SQL, DDL, CREATE commands are
Schema, Base and Table
Schema, Table and View
Base, Table and Schema
Key, Base and Table
Count function in SQL returns the number of
values.
distinct values.
groups.
columns.
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
The exists construct returns the value true, if the argument subquery is
empty
nonempty
contains null values
none of the above
Transaction processing is associated with everything below except
producing detail, summary, or exception reports.
recording a business activity.
confirming an action or triggering a response.
maintaining data.
The types of noiseless channels are
i) Selective Reject ARQ
ii) simplest protocol
iii) Go-Back-N ARQ
iv) Stop-and-Wait Protocol
i, ii only
ii and iv only
ii and iv only
i, iv only
The minimal set of super key is called
Primary key
Secondary key
Candidate key
Foreign key
Which of the following is also known as Offline storage ?
primary storage
secondary storage
tertiary storage
none of the above