If the closure of an attribute set is the entire relation then the attribute set is a
superkey
candidate key
primary key
not a key
Correct Answer :
A. superkey
Related Questions
The drawback of shadow paging technique are
Commit overhead
Data fragmentation
Garbage collection
All of these
Assume transaction A holds a shared lock R. If transaction B also requests for a shared lock on R.
It will result in a deadlock situation.
It will immediately be rejected.
It will immediately be granted.
It will be granted as soon as it is released by A .
It is an abstraction through which relationships are treated as higher level entities
Generalization.
Specialization.
Aggregation.
Inheritance.
_____ is a utility to capture a continuous record of server activity and provide auditing capability.
SQL server Profile
SQL server wizard.
SQL server service manager
SQL server setup
Which two files are used during operation of the DBMS?
Query languages and utilities
DML and query language
Data dictionary and transaction log
Data dictionary and query language
A relation is in attribute of other composite key. if an attribute of a composite key is dependent on an
2NF
3NF
BCNF
1NF
The collection of information stored in a database at a particular moment is called as ......
schema
instance of the database
data domain
independence
_____ command can be used to modify a column in a table
alter
update
set
create
The keyword to eliminate duplicate rows from the query result in SQL is
DISTINCT
NO DUPLICATE
UNIQUE
None of the above
The normal form that is not necessarily dependency preserving is
2NF
3NF
BCNF
4NF
Data items grouped together for storage purposes are called a
record
string
title
list
Maximum height of a B+ tree of order m with n key values is
Logm(n)
(m+n)/2
Logm/2(m+n)
None of these
Processed data is called _____
Raw data
Source
Information
Useful data
Given the following relation S(SNO,SNAME,CITY) write a query to update the value of CITY to KANPUR for the supplier S1.
UPDATE S CITY = KANPUR WHERE SNO=S1
UPDATE S SET CITY = KANPUR FOR SNO=S1
UPDATE S SET CITY = KANPUR WHERE SNO=S1
UPDATE S RENAME CITY = KANPUR WHERE SNO=S1
Which of the following is not a consequence of concurrent operations?
Lost update problem.
Update anomaly.
Unrepeatable read.
Dirty read.
In E-R Diagram total participation is represented by
Double lines
Single line
Dashed lines
Triangle
Which of the syntax is correct for insert statement?
i) insert into values
ii) insert into (column list) values
ii) insert into
i-only
ii-only
Both of them
None of them
Wait-for graph is used for
detecting view serializability.
detecting conflict serializability.
deadlock prevention
deadlock detection
Create a table with the following attributes: Employee(EMPNO integer, EMPNAME of 10 characters)
Create table Employee(EMPNO int, EMPNAME char(10));
Create table Employee(EMPNO integer, EMPNAME String(10));
Create table Emplo(EMPNO number, EMPNAME string);
Create table Emp(EMPNO int, EMPNAME char(10));
An advantage of views is
Data security
Derived columns
Hiding of complex queries
All of the above
In b-tree the number of keys in each node is than the number of its children.
one less
same
one more
half
What is data integrity?
It is the data contained in database that is non redundant.
It is the data contained in database that is accurate and consistent.
It is the data contained in database that is secured.
It is the data contained in database that is shared.
Relations produced from an E-R model will always be
First normal form.
Second normal form.
Third normal form.
Fourth normal form.
By ______ an area on disk in certain ways, one can make it represent a bit value of either zero (0) or one (1).
Vulcanizing
Galvanizing
Magnetizing
Passing UV rays
The division operator divides a dividend A of degree m+n by a divisor relation B of degree n and produces a result of degree
m - 1
m + 1
m * m
m
Which of the following ensures the atomicity of the transaction?
Transaction management component of DBMS
Application Programmer
Concurrency control component of DBMS
Recovery management component of DBMS
The common column is eliminated in
theta join
outer join
natural join
composed join
Relational Algebra does not have
Selection operator.
Projection operator.
Aggregation operators.
Division operator.
If the closure of an attribute set is the entire relation then the attribute set is a
superkey
candidate key
primary key
not a key
An advantage of the database management approach is
data redundancy increases
data is dependent on programs
data is integrated and can be accessed by multiple programs
none of the above