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
Correct Answer :
B. the correctness and completeness of the data in a database
Related Questions
Only one communication channel is needed rather than n channels to transmit data between two communicating devices
parallel
serial
analog
digital
An entity set which have sufficient attributes to form a primary key
Tree structure
Subtree structure
Strong entity set
Table structure
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
State which of the following statements are True
i) TCP is connection oriented but unreliable
ii) UDP is connection oriented but unreliable
iii) TCP is connectionless but reliable
iv) UDP is connectionless but reliable
i and ii only
ii and iii only
i and iii only
None of these
Triggers are also called
active rules
passive rules
inferences
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
View never contains derived columns.
True
False
Cant say
none
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
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
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.
Select the incorrect statement
BCNF is stronger than 3NF
Relational algebra is a non-procedural language
Every conflict serializable schedule is view serializable.
none of the above
What does the number of attributes in a relation is called?
Cardinality
Degree
Tuple
Order
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
In an Entity-Relationship Diagram Diamonds represents
Attributes
Multi-valued attributes
Weak entity set
Relationship sets
In ………… paging we make copy of the current page table.
physical
logical
shadow
duplicate
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 is not a constraint on a single relation?
check
unique
not null
is duplicate
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
The union of primary keys of a related entity becomes …………. Of a relation.
primarykey
superkey
candidatekey
foreignkey
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.
Which one of the following is provided by a data dictionary ?
User data
Database structure data
Sorted data
Functional data
Event condition action model is related to
Views
Cursors
Triggers
None of these.
A transaction which completes successfully is called
Granted
Committed
Compensated
Accomplished
Select the correct statement
i) Aggregate functions work on a group of data and return a single value.
ii) ODBC connects the frontend with the database without considering its compatibility
iii) View definition cant be used at multiple places through with clause .
i and ii only
ii and iii only
i and iii only
i only
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
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)
Functional dependencies are generalization of
Relation dependencies
Data dependencies
key dependencies
none of the above
The index table has …… Columns.
1
2
3
4
In two-phase locking
the data items are locked in growing phase.
the data items are released in shrinking phase.
Both A and B are true
Both A and B are false