A relation is in attribute of other composite key. if an attribute of a composite key is dependent on an
2NF
3NF
BCNF
1NF
Correct Answer :
B. 3NF
A relation is in 3 NF if an attribute of a composite key is dependent on an attribute of other composite key. (If an attribute of a composite key is dependent on an attribute of other composite key then the relation is not in BCNF, hence it has to be deco
Related Questions
Checkpoints are a part of
Recovery measures.
Security measures.
Concurrency measures.
uthorization measures.
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
What are the desirable properties of a decomposition
Partition constraint.
Dependency preservation.
Redundancy.
Security.
It is an abstraction through which relationships are treated as higher level entities
Generalization.
Specialization.
Aggregation.
Inheritance.
____ table store information about database or about the system.
SQL
System
Nested
None of these
The normal form that is not necessarily dependency preserving is
2NF
3NF
BCNF
4NF
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.
Union operator is a :
Unary Operator
Ternary Operator
Binary Operator
Not an operator
The ______ indexes are forced to store only record IDs in the data structure and require at least one additional I/O Operation to retrieve the actual record.
Clustered
Hashed
Un-clustered
Collision
_____ command can be used to modify a column in a table
alter
update
set
create
Cascading rollback is avoided in all protocol except
strict two-phase locking protocol.
tree locking protocol
two-phase locking protocol
validation based protocol.
A table can have only one
Secondary key
Alternate key
Unique key
Primary key
The clause in SQL that specifies that the query result should be sorted in ascending or descending order based on the values of one or more columns is
View
Order by
Group by
Having
The fact that information in the data warehouse changes far less often and may be regarded as non-real-time with periodic updating; This implies that data warehouses are _______
Volatile
Non - Volatile
Logical
Physical
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 DBMS is a ____ user if at most one user can use the system and is mostly restricted to personal computer systems.
None
Multi
Single
Concurrent
A relational database developer refers to a record as
an attribute
a tuple
a criteria
a relation
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));
The set of all values that can be taken by the attribute is called as _______ of the attribute.
Tuple
Cardinality
Degree
Domain
Immediate database modification technique uses
Both undo and redo.
Undo but no redo.
Redo but no undo.
Neither undo nor redo.
______is a special type of integrity constraint that relates two relations & maintains consistency across the relations.
Domain Integrity Constraints
Referential Integrity Constraints
Domain Constraints
Entity Integrity Constraints
The graphical representation of a query is .
B-Tree
graph
Query Tree
directed graph
As per equivalence rules for query transformation, selection operation distributes over
Union.
Set difference.
Intersection.
All of the above.
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
The fact that all employees of a particular organization should not have salaries more than $10000 is a _____ constraint.
Schema
Tuple
Domain
Relational
An outstanding functionality of SQL is its support for automatic_____ to the target data.
programming
navigation
functioning
notification
The relational model is based on the concept that data is organized and stored in two-dimensional tables called ______
Fields
Records
Relations
Keys
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;
According to the levels of abstraction, the schema at the intermediate level is called
Logical schema.
Physical schema.
Subschema.
None of the above.
In an ER diagram the ___shape specifies the Attibute and a ____ shape specifies the primary key attribute.
Oval; An oval with an underlined attribute
Circle; A circle with bolded attribute inside it
Diamond; A bolded attribute
Square; An attribute within the square