The keyword to eliminate duplicate rows from the query result in SQL is
DISTINCT
NO DUPLICATE
UNIQUE
None of the above
Correct Answer :
C. UNIQUE
Related Questions
DROP is a statement in SQL.
Query
Embedded SQL
DDL
DCL
The normal form that is not necessarily dependency preserving is
2NF
3NF
BCNF
4NF
_____ First proposed the process of normalization.
Edgar. W
Edward Stephen
Edgar F. Codd
Edward Codd
In a relational schema, each tuple is divided into fields called
Relations
Queries
Domains
All of the above
Relational Algebra does not have
Selection operator.
Projection operator.
Aggregation operators.
Division operator.
In SQL the statement select * from R, S is equivalent to
Select * from R natural join S.
Select * from R cross join S.
Select * from R union join S.
Select * from R inner join S.
When an E-R diagram is mapped to tables, the representation is redundant for
weak entity sets
weak relationship sets
strong entity sets
strong relationship sets
Cascading rollback is avoided in all protocol except
strict two-phase locking protocol.
tree locking protocol
two-phase locking protocol
validation based protocol.
Which of the following relational algebraic operations is not from set theory?
Union
Intersection
Cartesian Product
Select
Which of the following concurrency control schemes is not based on the serializability property?
Two - phase locking
Graph-based locking
Time-stamp based locking
None of these .
Which of the following is not a consequence of concurrent operations?
Lost update problem.
Update anomaly.
Unrepeatable read.
Dirty read.
The transactions like adding an employee, enrolling a student in a course are examples of _______
Logical
Physical
None
Theoretical
The set of all values that can be taken by the attribute is called as _______ of the attribute.
Tuple
Cardinality
Degree
Domain
The graphical representation of a query is .
B-Tree
graph
Query Tree
directed graph
According to the levels of abstraction, the schema at the intermediate level is called
Logical schema.
Physical schema.
Subschema.
None of the above.
Key to represent relationship between tables is called
primary key
secondary key
foreign key
none of the above
The statement that is executed automatically by the system as a side effect of the modification of the database is
backup
assertion
recovery
trigger
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
The common column is eliminated in
theta join
outer join
natural join
composed join
For using a specific database …………… command is used.
use database
database name use
Both A & B
None of them
Union operator is a :
Unary Operator
Ternary Operator
Binary Operator
Not an operator
Precedence graphs help to find a
Serializable schedule.
Recoverable schedule.
Deadlock free schedule.
Cascadeless schedule.
Change Staff table by removing default of Assistant for position column
ALTER TABLE Staff ALTER position DROP DEFAULT;
ALTER TABLE Staff ALTER position DEFAULT;
ALTER TABLE Staff ALTER DROP DEFAULT;
MODIFY Staff ALTER position DROP DEFAULT;
As per equivalence rules for query transformation, selection operation distributes over
Union.
Set difference.
Intersection.
All of the above.
Use of UNIQUE while defining an attribute of a table in SQL means that the attribute values are
distinct values
cannot have NULL
both (A) & (B)
same as primary key
In multiple granularity of locks SIX lock is compatible with
IX
IS
S
SIX
Which of the following statement on the view concept in SQL is invalid?
All views are not updateable
The views may be referenced in an SQL statement whenever tables are referenced.
The views are instantiated at the time they are referenced and not when they are defined.
The definition of a view should not have GROUP BY clause in it.
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
_____ 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
What is a disjoint less constraint?
It requires that an entity belongs to no more than one level entity set.
The same entity may belong to more than one level.
The database must contain an unmatched foreign key value.
An entity can be joined with another entity in the same level entity set.