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
Correct Answer :
C. Both A and B are true
Related Questions
Electromagnetic spectrum included in radiowaves are
i) Super High Frequency (SHF)
ii) Very High Frequency (VHF)
iii) Ultra High Frequency (UHF)
iv) High Frequencies (HF)
i, ii and iii only
i, ii and iv only
ii, iii and iv only
i, iii and iv only
The syntax to select all column from the table is
select all from tablename
select * from tablename
select from tablename
none of these
An association of several structure of a data base can be expressed graphically by?
Tuple
Record
Relationship
Field
Three SQL, DDL, CREATE commands are
Schema, Base and Table
Schema, Table and View
Base, Table and Schema
Key, Base and Table
A relation that has no partial dependencies is in which normal form
First
Second
Third
BCNF
An advantage of the database management approach is
data is dependent on programs.
data redundancy increases.
data is integrated and can be accessed by multiple programs.
none of the above.
Which of the following submit and execute query at run time?
Static SQL
Dynamic SQL
both
none of these
What is ACID properties of Transactions?
Atomicity, Consistency, Isolation, Database
Atomicity, Consistency, Isolation, Durability
Atomicity, Consistency, Inconsistent, Durability
Automatically, Concurrency, Isolation, Durability
The number of cursors depend on the
number of queries
number of attributes
size of memory area
none of these
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
In RDBMS, Data is presented as a collection of
Relation
Table
Attribute
Entity
Which command is used to cancel privileges granted through the GRANT command ?
CANCEL
OVER
STOP
REVOKE
A logical schema
is the entire database.
is a standard way of organizing information into accessible parts.
describes how data is actually stored on disk.
both A) and C)
Symbol to represent weak entity set in ER Model
Dotted rectangle
Square
Doubly outlined rectangle
Diamond
A functional dependency between two or more non-key attributes is called
Transitive dependency
Partial transitive dependency
Functional dependency
Partial functional dependency
Which one of the following is provided by a data dictionary ?
User data
Database structure data
Sorted data
Functional data
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.
Which of the following normalization is needed, if an attribute of a composite key is dependent on an attribute of the other composite key?
BCNF
Second
Third
Fourth
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
The maximum number of children in a B-tree of order m is
m+1
m
m-1
m/2
In a Hierarchical model records are organized as
Graph.
List.
Links.
Tree.
A …………… is a memory area where data are processed.
view
trigger
cursor
none of the above
Size of source and destination address in IP header
4 bits
8 bits
12 bits
32 bits
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
Select the incorrect statement(s)
i) Shared locks are compatible with each other.
ii) A relation which is in 3NF may have redundancy due to composite keys.
iii) A table in a database can have multiple indexes.
i only
ii, only
ii, iii only
none of the above
Aggregate functions are also called
serial functions
non-serial functions
row functions
column functions
The command used to delete a particular column in a relation
UPDATE
DROP
ALTER
DELETE
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
Data fragmentation is performed by the …… and each fragment is stored at…………..
DBMS, same site
OS ,same site
DBMS ,different site
OS ,different site
In mesh topology, if the number of devices is n , then the number of ports present in each device is
n
n+1
n-1
n/2