Which of the following works as a filter?
UPDATE
DROP
ALTER
SELECT
Correct Answer :
D. SELECT
Related Questions
The access protocol used by traditional Ethernet
CSMA/CA
CSMA/CD
CSMA
Token ring
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 method by which the structure of the database is modified to eliminate hidden dependencies and replacing groups is
Normalization
Indexing
Enforcing referential integrity
Enforcing data integrity
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
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
In an Entity-Relationship Diagram Diamonds represents
Attributes
Multi-valued attributes
Weak entity set
Relationship sets
In RDBMS, Data is presented as a collection of
Relation
Table
Attribute
Entity
Noisy channel has ……… .. types of protocols
two
three
four
none
Which of the following layer uses trailer of the frame for error detection?
Transport layer
Network layer
Datalink layer
None of these
RAID
Redundant Arrays of Independent Disks
Redundant Arrays of Independent Drives
Redundant Arrays of Interconnected Drives
Redundant Arrays of Interconnected Disks
In an E-R diagram attributes are represented by
rectangle.
square.
ellipse.
triangle.
DBMS helps achieve
Data independence
Centralized control of data
Neither A) nor B)
both A) and B)
The method of access which uses key transformation is known as
direct.
hash.
random.
sequential.
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
Encoding method which does not provide for synchronization
B8ZS
Manchester
RZ
NRZ-L
An entity set which have sufficient attributes to form a primary key
Tree structure
Subtree structure
Strong entity set
Table structure
A relation is said to be in ………. If it doesnt contain partial dependency
1NF
2NF
3NF
BCNF
The union of primary keys of a related entity becomes …………. Of a relation.
primarykey
superkey
candidatekey
foreignkey
Which of the following is not an Aggregate function?
Min
Max
Select
Avg
An operation that will increase the length of a list is
insert
modify
lookup
none of the above
Event condition action model is related to
Views
Cursors
Triggers
None of these.
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
Data Manipulation Language DML) is not to
Create information table in the Database
Insertion of new information into the Database
Deletion of information in the Database
Modification of information in the Database
The overall design of a database is called
Subschema of the database
Schema of the database
Structure of the database
View of the database
.................. 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
Three SQL, DDL, CREATE commands are
Schema, Base and Table
Schema, Table and View
Base, Table and Schema
Key, Base and Table
Which of the following is logical topology?
Bus
Ring
Star
None of these
The ________ states that a foreign key must either match a primary key value in another relation or it must be null.
entity integrity rule
referential integrity constraint
composite attribute
action assertion
Secondary storage
magnetic disk
magnetic tape
juke box
cache