Union operator is a :
Unary Operator
Ternary Operator
Binary Operator
Not an operator
Correct Answer :
C. Binary Operator
Related Questions
______ keyword is used to find the number of values in a column.
TOTAL
ADD
COUNT
SUM
The one guideline to be followed while designing the database is
A database design may be ambiguous.
It should avoid/reduce the redundancy.
Unrelated data should be in the same table so that updating the data will be easy.
An entity should not have attributes.
Precedence graphs help to find a
Serializable schedule.
Recoverable schedule.
Deadlock free schedule.
Cascadeless schedule.
Which one is true statement :
With finer degree of granularity of locking a high degree of concurrency is possible.
Locking prevents non-serializable schedules.
Locking cannot take place at field level.
An exclusive lock on data item X is granted even if a shared lock is already held on X.
The keyword to eliminate duplicate rows from the query result in SQL is
DISTINCT
NO DUPLICATE
UNIQUE
None of the above
Which is the best file organization when data is frequently added or deleted from a file?
Sequential
Direct
Index sequential
None of the above
Checkpoints are a part of
Recovery measures.
Security measures.
Concurrency measures.
uthorization measures.
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
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
A _____ is used to define overall design of the database
code
data definition language
application program
schema
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.
_______ product was acquired by Informix, integrated into its RDBMS and introduced as the Informix Universal Server an ORDBMS.
Star
llustar
SQL
Cygnus
Which of the following is not a property of transactions?
Atomicity
Concurrency
Isolation
Durability
Relationships among relationships can be represented in an-E-R model using
Aggregation
Association
Weak entity sets
Weak relationship sets
Processed data is called _____
Raw data
Source
Information
Useful data
______contains information that defines valid values that are stored in a column or data type.
Default
Index
Rule
View
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.
_____clause is an additional filter that is applied to the result.
Select
Order by
Group-by
Having
………………… approach reduces time and effort required for design and lesser risk in database management.
Single global database
Multiple databases
Top-down approach
None of the above
It is an abstraction through which relationships are treated as higher level entities
Generalization.
Specialization.
Aggregation.
Inheritance.
Relational Algebra is
Data Definition Language .
Meta Language
Procedural query Language
None of the above
Employees in a company are each assigned their own office, i.e. for each employee there exists a unique office and for each office there exists a unique employee; This statement is an example of ____ type of relation.
1:1
1: Many
Many: One
Many : Many
A _____ is a logical unit of database processing that includes one or more data access operations that can include insertion, deletion, modification or retrieval operations.
Database
Data
Transaction
Record
The values of the attribute describes a particular
Entity set
File
Entity instance
Organization
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;
What will be the number of columns and rows respectively obtained for the operation, A- B, if A B are Base union compatible and all the rows of a are common to B? Assume A has 4 columns and 10 rows; and B has 4 columns and 15 rows
4,0
0,0
4,5
8,5
Which normal form is considered adequate for normal relational database design?
2NF
5NF
4NF
3NF
The concept of mapping of ______ entity types is the concept in which the for each strong entity type E in the ER schema, create a relation R that includes all the simple attributes of E.
Regular
Irregular
None
Weak
The metadata is created by the
DML compiler
DML pre-processor
DDL interpreter
Query interpreter
The normalization was first proposed by .
Code
Codd
Boyce Codd
Boyce