A lock that allows concurrent transactions to access different rows of the same table is known as a
Field-level lock
Row-level lock
Table-level lock
Database-level lock
Correct Answer :
A. Field-level lock
Related Questions
Technique(s) used for data recovery after any failure
Logging
Recovery manager
Both A and B are true
Both A and B are false
The class based addressing is known as
Classless addressing
Classful addressing
Classified addressing
Classical addressing
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.
Unwanted energy from source other than the transmitter.
Attenuation
Distortion
Delay
Noise
Secondary storage
magnetic disk
magnetic tape
juke box
cache
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
.................. means sending a digital signal over a channel without changing the digital signal to an analog signal.
Baseband transmission
Broadband transmission
Digital transmission
Analog transmission
In this data model each record can hae more than one parent
Hierarchical model
E-R model
Network based model
none of these
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
The host part in a class A type of an IP address has
12 bits
16 bits
24 bits
28 bits
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
The output of the Data Definition Language is stored in the
view table
schema
metadata
all of the above.
FDDI protocol operates in
i) Transport layer
ii) Network layer
iii) Datalink layer
iv) Physical layer
i and ii only
ii and iii only
i and iii only
iii and iv only
Which of the following is not proper state of transaction ?
Partially aborted
Partially committed
Aborted
Committed
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
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
Symbol to represent weak entity set in ER Model
Dotted rectangle
Square
Doubly outlined rectangle
Diamond
The number of cursors depend on the
number of queries
number of attributes
size of memory area
none of these
Technique used in log based recovery
Immediate database modification
Graph-based recovery
key dependencies
none of the above
As a side-effect of database update ,the system automatically executes a statement called
a view
a grant permission
a trigger
all 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.
Which one of the following is provided by a data dictionary ?
User data
Database structure data
Sorted data
Functional data
A subschema expresses
the logical view.
the physical view.
the external view.
all of the above.
DBMS utility which allows to reconstruct the correct state of database from the backup and history of transactions
Backup
Recovery
Grant
Troubleshooting
DECLARE is a(an)
executable statement.
declarative statement.
Ordered file
none of the above
Benefit of database normalization is
smaller number of tables
higher query processing efficiency
reduced I/O for most queries
reduced data redundancy
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
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
The minimal set of super key is called
Primary key
Secondary key
Candidate key
Foreign key