Eliminate Redundant Relationships
Relationship between two entities that is equivalent to another Relationship between two entities that transitive through an intermediate entity is called Redundant Relationships.
An instance, an I.T. Company is constructed with many Building and Workstations that I.T. Company is formed with many Technical and Non-Technical Departments. Each Department is formed with many Employees. Most of the Workstations are allotted to Employees and some workstations are empty that reserved for new Employees.
When, you focus the diagram from Left to Right side, the diagram representing that Every Department is allotted with one or many Workstations and Each Department must have one or many Employees. Every Employee is allotted with one Workstation and Each Employee must have a Workstation by representing the Connectivity and Cardinality of Relationship Mandatory Symbol.
When, you focus the diagram from Right to Left side, the diagram representing that Every Workstation is allocated for an Employee and some Workstations are not allocated to any Employee. Every Employee must have a Department by representing the Connectivity and Cardinality of Relationship Mandatory Symbol.
Relationship between Department and Workstation entities that is equivalent to another Relationship between Employee and Workstation entities that transitive through an intermediate Employee entity is called Redundant Relationships. Redundant Relationships are produces Data Redundant that can avoid when eliminate one Relationship.
When, you focus the diagram from Left to Right side, the diagram representing that Every Department must have one or many Employees. Every Employee is allotted with one Workstation and Each Employee must have a Workstation by representing the Connectivity and Cardinality of Relationship Mandatory Symbol.
When, you focus the diagram from Right to Left side, the diagram representing that Every Workstation is allocated for an Employee and some Workstations are not allocated to any Employee. Every Employee must have a Department by representing the Connectivity and Cardinality of Relationship Mandatory Symbol.
Relationship between two entities that is equivalent to another Relationship between two entities that transitive through an intermediate entity is called Redundant Relationships.
An instance, an I.T. Company is constructed with many Building and Workstations that I.T. Company is formed with many Technical and Non-Technical Departments. Each Department is formed with many Employees. Most of the Workstations are allotted to Employees and some workstations are empty that reserved for new Employees.
When, you focus the diagram from Left to Right side, the diagram representing that Every Department is allotted with one or many Workstations and Each Department must have one or many Employees. Every Employee is allotted with one Workstation and Each Employee must have a Workstation by representing the Connectivity and Cardinality of Relationship Mandatory Symbol.
When, you focus the diagram from Right to Left side, the diagram representing that Every Workstation is allocated for an Employee and some Workstations are not allocated to any Employee. Every Employee must have a Department by representing the Connectivity and Cardinality of Relationship Mandatory Symbol.
Relationship between Department and Workstation entities that is equivalent to another Relationship between Employee and Workstation entities that transitive through an intermediate Employee entity is called Redundant Relationships. Redundant Relationships are produces Data Redundant that can avoid when eliminate one Relationship.
When, you focus the diagram from Left to Right side, the diagram representing that Every Department must have one or many Employees. Every Employee is allotted with one Workstation and Each Employee must have a Workstation by representing the Connectivity and Cardinality of Relationship Mandatory Symbol.
When, you focus the diagram from Right to Left side, the diagram representing that Every Workstation is allocated for an Employee and some Workstations are not allocated to any Employee. Every Employee must have a Department by representing the Connectivity and Cardinality of Relationship Mandatory Symbol.
 Your Comment To AUTHOR |
|
Download e-Book 
Copyright © 2010 data-e-education.com. All rights reserved.
