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.
Correct Answer :
C. Operationally, if X is deleted, so is Y.
Related Questions
If an entity can belong to only one lower level entity then the constraint is
disjoint
partial
overlapping
single
The ______ language consists of SQL statements for operating on the data (insert, Modify, Delete) in tables that already exist.
Data Manipulation
Data Definition
Data Control
None
____specifies a search condition for a group or an aggregate.
GROUP BY Clause
HAVING Clause
FROM Clause
WHERE Clause
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
Which of the following relational algebraic operations is not from set theory?
Union
Intersection
Cartesian Product
Select
The rule that a value of a foreign key must appear as a value of some specific table is called a
Referential constraint.
Index.
Integrity constraint.
Functional dependency.
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
The metadata is created by the
DML compiler
DML pre-processor
DDL interpreter
Query interpreter
The statement that is executed automatically by the system as a side effect of the modification of the database is
backup
assertion
recovery
trigger
_____ command can be used to modify a column in a table
alter
update
set
create
Grant and revoke are _____ statements.
TCL
DCL
DDL
DML
Precedence graphs help to find a
Serializable schedule.
Recoverable schedule.
Deadlock free schedule.
Cascadeless schedule.
DROP is a statement in SQL.
Query
Embedded SQL
DDL
DCL
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
In an ER model,_____ is described in the database by storing its data.
Entity
Attribute
Relationship
Notation
The relational model is based on the concept that data is organized and stored in two-dimensional tables called ______
Fields
Records
Relations
Keys
The transactions like adding an employee, enrolling a student in a course are examples of _______
Logical
Physical
None
Theoretical
______ keyword is used to find the number of values in a column.
TOTAL
ADD
COUNT
SUM
Which of the following is not a characteristic of a relational database model?
Table
Tree like structure
Complex logical relationship
Records
Processed data is called _____
Raw data
Source
Information
Useful data
Which of the following aggregate functions does not ignore nulls in its results?.
COUNT .
COUNT (*)
MAX
MIN
Which of the following is not a recovery technique?
Deferred update
Immediate update
Two-phase commit
Shadow paging
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
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
A relational database developer refers to a record as
an attribute
a tuple
a criteria
a relation
Which of the following ensures the atomicity of the transaction?
Transaction management component of DBMS
Application Programmer
Concurrency control component of DBMS
Recovery management component of DBMS
______defines the structure of a relation which consists of a fixed set of attribute-domain pairs.
Instance
Program
Schema
Super Key
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
_____ 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
Immediate database modification technique uses
Both undo and redo.
Undo but no redo.
Redo but no undo.
Neither undo nor redo.