Database Reference
In-Depth Information
23.4.1 Hybrid Approach A
In the Hybrid Approach A, a relational database is accessed by an OO user interface.
This means that the application development is done via an OO Programming Language
(OOPL), CASE tool, or RAD tool.
There is no shortage of OOPL (some of them pure OOPLs, others are hybrid OOPLs).
The more popular ones include C++, Java, C#, and Object Pascal. There are many object-
oriented CASE (OO-CASE) tools and RAD tools that support this approach. They include
(but are not confined to) products such as Team Developer, Delphi, Oracle JDeveloper,
WebSphere, NetBeans etc.
Three advantages of this approach are as follows:
1.
It can facilitate
legacy systems
(software systems based on old
technology), which are prevalent in large organizations.
2.
It facilitates peaceful coexistence of traditional and more
contemporary system approaches.
3.
It reaps the benefits of a relational database and OO
application development.
The main disadvantage of the approach is that it does not address the earlier
mentioned situations that warrant OO database design. However, the skillful database
designer can use techniques mentioned in Chapter 3 for implementing relationships
such as subtype, component and aggregation.
23.4.2 Hybrid Approach B
In this approach, a relational/object database (often referred to as a universal database) is
accessed via an OO user interface. Like the Hybrid Approach A, application development
is done via an OOPL, OO-CASE tool, or RAD tool.
The universal database supports both the relational database as well as the
OO database. The designer can therefore make critical decisions as to which approach
is preferred, given the scenario. The skillful database designer also has the flexibility of
employing techniques mentioned in Chapter 3 for implementing relationships such as
sub-type, component and aggregation.
Several of the leading software engineering companies have in recent times,
introduced products that support object databases. Examples include:
•
IBM's DB2 Universal
•
Oracle Universal Database Server
•
Informix's Universal Data Option for its Dynamic Server
