If both the functional dependencies : X�Y and Y�X hold for two attributes X and Y then the relationship between X and Y is
M:N
M:1
1:M
Correct Answer :
C.
Related Questions
______ keyword is used to find the number of values in a column.
TOTAL
ADD
COUNT
SUM
The part of a database management system which ensures that the data remains in a consistent state is
authorization and integrity manager
buffer manager
transaction manager
file manager
In multiple granularity of locks SIX lock is compatible with
IX
IS
S
SIX
It is an abstraction through which relationships are treated as higher level entities
Generalization.
Specialization.
Aggregation.
Inheritance.
In a relational schema, each tuple is divided into fields called
Relations
Queries
Domains
All of the above
If an entity can belong to only one lower level entity then the constraint is
disjoint
partial
overlapping
single
_____ First proposed the process of normalization.
Edgar. W
Edward Stephen
Edgar F. Codd
Edward Codd
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.
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
A _____ is used to define overall design of the database
code
data definition language
application program
schema
Precedence graphs help to find a
Serializable schedule.
Recoverable schedule.
Deadlock free schedule.
Cascadeless schedule.
____specifies a search condition for a group or an aggregate.
GROUP BY Clause
HAVING Clause
FROM Clause
WHERE Clause
The collection of information stored in a database at a particular moment is called as ......
schema
instance of the database
data domain
independence
Relational Algebra is
Data Definition Language .
Meta Language
Procedural query Language
None of the above
Dependency preservation is not guaranteed in
BCNF
3NF
PJNF
DKNF
Relationships among relationships can be represented in an-E-R model using
Aggregation
Association
Weak entity sets
Weak relationship sets
A ____ key specifies a uniqueness constraint that no two distinct tuples in any state r of relation R can have the same value for super key.
Sub
Parent
Candidate
Super
Isolation of the transactions is ensured by
Transaction management
Application programmer
Concurrency control
Recovery management
The normal form that is not necessarily dependency preserving is
2NF
3NF
BCNF
4NF
Immediate database modification technique uses
Both undo and redo.
Undo but no redo.
Redo but no undo.
Neither undo nor redo.
HSAM stands for ……….
Hierarchic Standard Access Method
Hierarchic Sequential Access Method
Hierarchic Sequential and Method
Hierarchic Standard and Method
DROP is a statement in SQL.
Query
Embedded SQL
DDL
DCL
The data models defined by ANSI/SPARC architecture are
Conceptual, physical and internal
Conceptual, view and external
Logical, physical and internal
Logical, physical and view
Tree structures are used to store data in
Network model.
Relational model.
Hierarchical model.
File based system.
A table can have only one
Secondary key
Alternate key
Unique key
Primary key
In an E-R diagram double lines indicate
Total participation.
Multiple participation.
Cardinality N.
None of the above.
Between DRAM and magnetic disk storage another form of memory, called ______ memory is becoming common because it is non volatile.
RAM
Flash
Hard Disk
Secondary
Which of the following is not a property of transactions?
Atomicity
Concurrency
Isolation
Durability
If two relations R and S are joined, then the non matching tuples of both R and S are ignored in
left outer join
right outer join
full outer join
inner join
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