The ability to modify the conceptual schema without causing any change to the application program is known as
Physical data independence
Logical data independence
External data independence
Static data
Correct Answer :
B. Logical data independence
Related Questions
Which of the following extracts its data from the result of an SQL SELECT statement.
View
Synonym
Sequence
Transaction
An entity set which have sufficient attributes to form a primary key
Tree structure
Subtree structure
Strong entity set
Table structure
The minimal set of super key is called
Primary key
Secondary key
Candidate key
Foreign key
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
Mail services are available to network users through the
Session layer
Presentation layer
Application layer
Transport layer
Only one communication channel is needed rather than n channels to transmit data between two communicating devices
parallel
serial
analog
digital
Data fragmentation is performed by the …… and each fragment is stored at…………..
DBMS, same site
OS ,same site
DBMS ,different site
OS ,different site
The transaction consists of all statements executed between
the begin transaction and end transaction
the start transaction and end transaction
the begin transaction and finish transaction
none of the above.
The method of access which uses key transformation is known as
direct.
hash.
random.
sequential.
Query processing is
converting data to insert in a database
translation of query to lower form
range of activities involved in extracting data from a database
none of the above
Volatile storage
loses its contents when power is switched off.
doesnt loses its contents when power is switched off.
creates backup when power is switched off.
none
Benefit of database normalization is
smaller number of tables
higher query processing efficiency
reduced I/O for most queries
reduced data redundancy
In which of the random-access method, stations do not sense the medium?
ALOHA
ETHERNET
CSMA/CA
CSMA/CD
A type of query that is placed within a WHERE or HAVING clause of another query is called
Super query
Sub query
Master query
Multi-query
In an Entity-Relationship Diagram Diamonds represents
Attributes
Multi-valued attributes
Weak entity set
Relationship sets
Generalization is a
top-down approach.
bottom-up approach.
left-right approach.
none of the above
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
An association of several structure of a data base can be expressed graphically by?
Tuple
Record
Relationship
Field
A …………… is a memory area where data are processed.
view
trigger
cursor
none of the above
Which of the following produces the relation that has attributes of R1 and R2
Cartesian product
Difference
Intersection
Product
Symbol to represent weak entity set in ER Model
Dotted rectangle
Square
Doubly outlined rectangle
Diamond
The syntax to select all column from the table is
select all from tablename
select * from tablename
select from tablename
none of these
Which of the following is not proper state of transaction ?
Partially aborted
Partially committed
Aborted
Committed
In case of entity integrity, the primary key may be
not Null
Null
both Null & not Null.
any value.
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
Which of the following is also known as Offline storage ?
primary storage
secondary storage
tertiary storage
none of the above
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.
In the architecture of a database system external level is the
physical level.
logical level.
conceptual level
view level.
Data independence means
data is defined separately and not included in programs.
programs are not dependent on the physical attributes of data.
programs are not dependent on the logical attributes of data.
both B) and C).
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