Noisy channel has ……… .. types of protocols
two
three
four
none
Correct Answer :
B. three
Related Questions
DECLARE is a(an)
executable statement.
declarative statement.
Ordered file
none of the above
The privilege lists include
i) select
ii) insert
iii) update
iv) delete
only i)
only i) ii)
only i) ii) iii)
i) ii) iii) iv)
Noisy channel has ……… .. types of protocols
two
three
four
none
Data integrity refers to
the uniqueness of the data in a database
the correctness and completeness of the data in a database
the un redundancies of the data in a database
Data independence of the database
Which one of the following statements is false?
The data dictionary is normally maintained by the database administrator.
Data elements in the database can be modified by changing the data dictionary.
The data dictionary contains the name and description of each data element.
The data dictionary is a tool used exclusively by the database administrator.
Every Boyce-Codd normal form is in
3NF
2NF
1NF
none of the above
Which of the following Key is used to represent relationship between the tables?
Primary key
Secondary Key
Foreign Key
None of these
Size of source and destination address in IP header
4 bits
8 bits
12 bits
32 bits
.................. occurs due to velocity of propagation the frequency varies. Thus various frequency components of a signal arrive at the receiver at different times.
Noise
Delay distortion
Attenuation distortion
Dispersion
In which of the following transmissions, we can send data by grouping n bits at a time instead of a single bit?
parallel
serial
analog
digital
Technique used in log based recovery
Immediate database modification
Graph-based recovery
key dependencies
none of the above
What is the result of the following SQL statement ?
SELECT A.emp_Name, B.ph_num
FROM emp A LEFT OUTER JOIN phone B
ON A. emp_ID = B.emp_ID
A list of employees phone number
A list of all employees that have spouses, with phone number included in the list
A list of all employees names, including the phone number if they have one
Two lists : One list of employees, the other of phone numbers
In an Entity-Relationship Diagram Diamonds represents
Attributes
Multi-valued attributes
Weak entity set
Relationship sets
In the architecture of a database system external level is the
physical level.
logical level.
conceptual level
view level.
A relation that has no partial dependencies is in which normal form
First
Second
Third
BCNF
A …………… is a memory area where data are processed.
view
trigger
cursor
none of the above
In two-phase locking protocol the two phases are
growing phase and shrinking phase
execution phase and blocking phase.
running phase and sleeping phase.
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
Triggers are also called
active rules
passive rules
inferences
none of the above
The left outer join takes all tuples
in the left relation which didnt match with any tuple in right relation
in the left relation which matched with a tuple in right relation
in the right relation which didnt match with any tuple in left relation
in the right relation which matched with a tuple in left relation
Commit operation …………… writes the changes made to the database.
temporarily
permanently
none of these
all of the above
Which of the following is also known as Offline storage ?
primary storage
secondary storage
tertiary storage
none of the above
Which of the following is/are error-free channel(s)
i) Noisy channel
ii) Noiseless channel
i only
ii only
Both
None of these
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.
Symbol to represent weak entity set in ER Model
Dotted rectangle
Square
Doubly outlined rectangle
Diamond
The degree of the table with 500 rows and 7 columns is
500
7
3500
none of these
.................. 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
What is ACID properties of Transactions?
Atomicity, Consistency, Isolation, Database
Atomicity, Consistency, Isolation, Durability
Atomicity, Consistency, Inconsistent, Durability
Automatically, Concurrency, Isolation, Durability
Radio frequencies below ............. are more suitable for omnidirectional applications.
300MHz
1GHz
5GHz
10 GHz
Which of the following submit and execute query at run time?
Static SQL
Dynamic SQL
both
none of these