Database Reference
In-Depth Information
10.2.2.3 Data Integration
In this model, integration is accomplished by bypassing the existing application business logic and
accessing directly the data created, processed, and stored by each of the corresponding applications.
For instance, an Oracle-based billing system can be integrated with an IBM-based customer order
system using the database gateway technology that integrates the DB2 database with the Oracle
database.
This has been one of the earliest models applied for accessing information from databases
including
◾
Batch file transfer
◾
Open Database Connectivity (ODBC)
◾
Database access middleware
◾
Data transformation
The data integration model provides greater flexibility than the presentation integration model: it
simplifies access to data from multiple sources and also allows the data to be reused across other
applications. However, integrating at the data level necessitates rewriting of any functionality
required by each of the applications that imply much larger effort for avoiding inconsistencies,
standardizing, testing, and debugging for each of the applications on an ongoing basis. Since this
model is highly sensitive to changes in the data models for each of the applications, this integration
model is not very amenable for change and maintenance.
10.3 Service-oriented Architecture (SoA)
An SOA focuses on the message-based interactions of components in a network rather than the
details of individual component implementation. An SOA (see Figure 10.2) relates three compo-
nent roles and three operations between the roles in support of dynamic, automated discovery and
use of services:
Service
Service
provider
Service
description
Publish
Bind
Service
description
Service
registry
Service
client
Find
Figure 10.2
Web service roles and operations.
