According to the levels of abstraction, the schema at the intermediate level is called
Logical schema.
Physical schema.
Subschema.
None of the above.
Correct Answer :
D. None of the above.
According to the levels of abstraction, the schema at the intermediate level is called conceptual schema.
Related Questions
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 views is
Data security
Derived columns
Hiding of complex queries
All of the above
Union operator is a :
Unary Operator
Ternary Operator
Binary Operator
Not an operator
Shadow paging has
no redo
no undo
redo but no undo
neither redo nor undo
In an ER model,_____ is described in the database by storing its data.
Entity
Attribute
Relationship
Notation
In an E-R diagram double lines indicate
Total participation.
Multiple participation.
Cardinality N.
None of the above.
Which of the following relational algebraic operations is not from set theory?
Union
Intersection
Cartesian Product
Select
Key to represent relationship between tables is called
primary key
secondary key
foreign key
none of the above
An outstanding functionality of SQL is its support for automatic_____ to the target data.
programming
navigation
functioning
notification
Which of the following is not comparison operator?
<>
<
=<
>=
_____is a full form of SQL.
Standard query language
Sequential query language
Structured query language
Server side query language
According to the levels of abstraction, the schema at the intermediate level is called
Logical schema.
Physical schema.
Subschema.
None of the above.
Which of the following is not a characteristic of a relational database model?
Table
Tree like structure
Complex logical relationship
Records
In E-R Diagram total participation is represented by
Double lines
Single line
Dashed lines
Triangle
E-R Modeling is achieved by using ____ diagrams
DFD
Flowcharts
Gantt Charts
E-R
A data type or format is specified for each _________
Relation
Tuple
Database
Domain
The keyword to eliminate duplicate rows from the query result in SQL is
DISTINCT
NO DUPLICATE
UNIQUE
None of the above
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 fact that all employees of a particular organization should not have salaries more than $10000 is a _____ constraint.
Schema
Tuple
Domain
Relational
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
Which of the following is a reason to model data?
Understand each user's perspective of data
Understand the data itself irrespective of the physical representation
Understand the use of data across application areas
All of the above
Grant and revoke are _____ statements.
TCL
DCL
DDL
DML
The statement that is executed automatically by the system as a side effect of the modification of the database is
backup
assertion
recovery
trigger
A logical schema
is the entire database
Describes how data is actually stored on disk.
is a standard way of organizing information into accessible parts.
All of the above
Relational Algebra does not have
Selection operator.
Projection operator.
Aggregation operators.
Division operator.
In an E-R, Y is the dominant entity and X is a subordinate entity. Then which of the following is incorrect :
Operationally, if Y is deleted, so is X
existence is dependent on Y.
Operationally, if X is deleted, so is Y.
Operationally, if X is deleted, & remains the same.
The cost of reading and writing temporary files while evaluating a query can be reduced by
building indices
pipelining
join ordering
none of the above
If a transaction T has obtained an exclusive lock on item Q, then T can
read Q
write Q
both read and write Q
write Q but not read Q
The transactions like adding an employee, enrolling a student in a course are examples of _______
Logical
Physical
None
Theoretical
Processed data is called _____
Raw data
Source
Information
Useful data