ENHANCED ENTITY RELATIONSHIP Flashcards
The ER model supported with additional semantic concepts
Enhanced Entity-Relationship model
modified True or False
Specialization and Generalization are the main concepts in representing EER model.
True
Identification
an entity type that includes distinct subclasses that require to be represented in
a data model.
Superclass
Identification
an entity type that has a distinct role and is also a member of a superclass
Subclass
Identification
The relationship between a superclass and any of its subclasses is called
superclass/subclass relationship
Identification
a class can have subclasses that inherit its attributes and the ability to
participate in the same relationships.
Attribute Inheritance
Identification
It is the process of minimizing the differences between entities by identifying their common features
It has a bottom-up approach
Generalization
Identification
It is the process of maximizing the differences between members of an entity by identifying distiguishing characteristics.
It has a top-down approach
Specialization
Identification
An entity can be a member of only one subclasses of specialization
Disjointed Constraint
It is presented by a d
Disjointed
Identification
What kind of constraint is an overlapping specialization?
Disjointed Constraint
It is presented by a o
An entity maybe a member of one or more subclass of a
specialization.
Identification
A specialization with a ____ ____________ specifies that every entity in the superclass must be a member of a sublass in the specialization.
Participation Constraint
It is represented by two line drawn between the sublass and the specialization circle.
total participation
Identification
The entity can not participate or does not need to participate in any of the subclasses of a specialization
Participation Constraint
It is represented by a line drawn between the sublass and the specialization circle.
Partial Participation
