Transaction access data using two operations
read(), print()
read(), write()
scan(), write()
none of the above
Correct Answer :
B. read(), write()
Related Questions
B-Tree is used for
searching data
storing data
both A and B
none of these
Which of the following is not a database object?
index
sequence
cursor
trigger
Aggregate functions are also called
serial functions
non-serial functions
row functions
column functions
The exists construct returns the value true, if the argument subquery is
empty
nonempty
contains null values
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
In RDBMS, Data is presented as a collection of
Relation
Table
Attribute
Entity
Which of the following will NOT eliminates the ambiguities of a null value?
Define the attribute as required
Define subtypes
Define each attribute as having an initial value that is recognized as blank
Define supertypes
Generalization is a
top-down approach.
bottom-up approach.
left-right approach.
none of the above
Which of the following is not proper state of transaction ?
Partially aborted
Partially committed
Aborted
Committed
What is the max data capacity of STP?
1 Gbps
56 Mbps
100 Mbps
256 Mbps
Extended Entity Relationship model consists of which of the following
i) Specialization
ii) Generalization
iii) Categorization
i and ii only
ii and iii only
i and iii only
All i, ii iii
Database locking concept is used to solve the problem of
Lost Update
Uncommitted Dependency
Inconsistent Data
All of the above
The database environment has all of the following components except:
users.
separate files.
database.
database administrator.
A data manipulation command the combines the records from one or more tables is called
SELECT
PROJECT
JOIN
PRODUCT
Log into a computer across an internet
IMAP
TELNET
POP3
Infrared
By default a user who has been granted some form of authorization
is allowed to pass them to others
is not allowed to pass them to others
may be or may not be allowed to pass them to others
none
A transaction is said to have terminated if it has
either committed or aborted
either partially committed or aborted
either committed or failed
none of these
Full form of CIDR
Classful Inter Domain Routing
Classless International Domain Routing
Classless Inter Domain Routing
none of these
Commit operation …………… writes the changes made to the database.
temporarily
permanently
none of these
all of the above
Consider the join of a relation R with relation S. If R has m tuples and S has n tuples,
then the maximum size of join is:
mn
m+n
m+n)/2
2 m+n)
Benefit of database normalization is
smaller number of tables
higher query processing efficiency
reduced I/O for most queries
reduced data redundancy
Which of the following is a classical approach to database design?
Left Right approach
Right Left approach
Top Down approach
Bottom Up approach
Select the incorrect statement(s)
i) Foreign key values can be left blank
ii) In SQL duplicates may be present
iii) Theta join operation doesnt remove duplicate columns.
iv) NULL value means string of blank characters.
i ,iii only
ii, iv only
iii, iv only
ii, iii, iv
What does a field or a combination of fields that has a unique value called ?
Foreign key
Secondary key
Primary key
Alternate key
Primary storage
magnetic disk
magnetic tape
juke box
cache
Select the incorrect statement
View is derived from other tables.
Once a transaction has executed commit work its effect cant be undone by rollback work .
The input to the aggregate function avg can be non numeric data types
A primary key can never be null.
The command used to delete a particular column in a relation
UPDATE
DROP
ALTER
DELETE
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
.................. 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
The physical location of a record is determined by a mathematical formula that transforms
a file key into a record location is :
B-Tree File
Hashed File
Indexed File
Sequential file.