Database Reference
In-Depth Information
OVERVIEW OF OBJECT-BASED MODELING
Data modeling deals with creating data models to represent real-world information.
Object technology relates to the treatment of business objects, their relationships,
and how they interact with one another. Object-based data modeling is a method
or discipline that combines the concepts of data modeling and object technology.
You make use of both concepts and arrive at a method to represent real-world
information. That is, you look for business objects in the real world, relate real-world
information with the business objects, and use this association to build a data model.
Obviously then, the modeling method centers on the business objects. Figure 6-1
expresses this merging of the two concepts in object-based data modeling.
A Generic Data Model
First of all, the object-based data model is a generic data model. Let us examine the
significance and implications of this statement. What are the types of databases that
are being implemented in organizations? You hear about an organization using a
specific database product from a particular vendor. For example, the database could
be an Oracle database, an Informix database, or a Microsoft SQL Server database.
Or the database could be an IBM IMS database.
Oracle, Informix, and SQL Server databases are based on the relational model.
The relational model is a data model in which all data are perceived as two-
dimensional tables. On the other hand, the IMS database is based on the hierar-
chical model. The hierarchical model is also a data model but is a model in which
all data are perceived as hierarchical data segments with parent-child relationships.
The relational model and the hierarchical model are specific models based on
defined conventions on the arrangement of the components. These two models are
specific conventional models.
REAL-WORLD
INFORMATION
BUSINESS
OBJECTS,
CHARACTERISTICS,
RELATIONSHIPS,
BUSINESS RULES
Modeling Components
NOTATIONS
REPRESENTATION
REPLICA BUILDING
RULES
PROCEDURES
REPRESENTATION
Object-Oriented Concepts
OBJECTS
OBJECT IDENTITY
CLASSES (SETS)
ATTRIBUTES
INHERITANCE
OF OBJECTS,
CHARACTERISTICS,
RELATIONSHIPS,
BUSINESS RULES
DATA MODEL
Figure 6-1
Object technology and data modeling.
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