Database Reference
In-Depth Information
REVIEW OF OBJECT-BASED DATA MODEL
As we conclude our discussion, let us recapitulate what we covered on this impor-
tant topic. Object-based data modeling is a natural, intuitive method of represent-
ing real-world information requirements. In the real world, most commonly you
notice business objects. This modeling technique provides components to represent
business objects, their characteristics, and their interactions.
Summary of Components
You can create a true data model for any set of real-world information require-
ments by using the following basic components, showing these with standard nota-
tions or symbols:
Object Set.
To represent a business object.
Attribute.
To represent an inherent or intrinsic characteristic of an object.
Identifier.
An attribute or set of attributes whose values will uniquely identify indi-
vidual instances of an object.
Relationship.
Direct association between instances of objects.
Cardinality Indicators.
Set of values to denote the minimum and maximum number
of instances that may participate in relationships between objects.
Generalization/Specialization.
To represent a superset and its subsets.
Comprehensive Data Model Diagram
Figure 6-28 presents a data model diagram for manufacturing operations.
Carefully note each component in the diagram. Study the various object sets,
relationships, and cardinality indicators and also observe the special cases. Even
though the data model represents many aspects of real-world information require-
ments, note that the whole model is constructed with only the basic components
listed above.
CHAPTER SUMMARY
•
Object-based data modeling based on both object technology and data mod-
eling is an effective method focusing on business objects.
•
The object-based data model is a generic model that has several advantages:
universal model, true replica, free from restraints, easily transformable, and
intuitive.
•
The components or building blocks of the data model are object set, attribute,
identifier, relationship, cardinality indicators, generalization/specialization.
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