Determining the implementation of the multitier model involves the recognition and evaluation of several factors. Primarily, organization business management, in conjunction with the information technology department, must develop a vision and scope for the application. Once the technical evaluation of OLTP multitier implementation begins, the scope of how the OLTP application will satisfy business needs should already be complete, supplemented with appropriate documentation.
In addition, business rule discovery and documentation should also be completed and well understood by all parties involved in the development of the application. Once the business rules have been finalized, OLTP strategy evaluations can begin.
Determine the Presentation Layer
The affirmation of the client type will serve as the foundation for the remainder of the OLTP model planning process. A thin client is preferable to a thick client because of ease of design, distribution and management.
Determining the client type involves selecting the platform on which the client will be built. Thin clients can be constructed using Active Server Pages in conjunction with VBScript or Java and distributed in an Internet and Intranet environment. Clients can also be Visual Basic executables, Visual Studio clients as well as comprised of other technologies such as Cold Fusion.
The type of thin client is usually a function of the organizations developers core skill set. An organizations management may decide to outsource the client creation process in favor of desired functionality (i.e., an Internet distributed application as opposed to a Visual Basic executable).
Determine the Middle Tier
The technologies involved in the middle tier are partially determined by the type of client that the organization plans to deploy. The complexity of the business rules and logic in conjunction with other factors also contribute to the evaluation and approval of middle tier technologies. Factors such as user community size, network traffic as well as client management and administration requirements all assist in determining which technologies will be deployed as part of the middle tier.
Microsoft Transaction Server
Client Load balancing including distribution and management of multiple client transactions
Management of Business Objects and Rules
Direct communication with the SQL Server 7.0 data tier
Microsoft Internet Information Server
Web Application Services including secured authentication of clients (users)
Hosting of dynamic web content including Active Server applications and other Internet distributed applications
Support of transactional web applications
Determine the Data tier
The data platform chosen by the organization will be a function of the businesses existing database technologies, the capability of the database to integrate and merge heterogeneous data from various sources as well as the personnel to assist in development and maintenance of the RDBMS.
SQL Server 7.0s features lower total cost of ownership, the time required for traditional DBA activities as well as supplement the consolidation and presentation of data from relational and non-relational sources. Using features like Data Transformation Services (DTS), OLE DB, as well as its enhanced and redesigned transactional management system, SQL Server 7.0 is often the optimal choice for an organizations OLTP needs.
SQL Server Technologies
Data Transformation Services (DTS) for the ETL of relational and non-relational data.
Reduction of administrative tasks through increased dynamic resource allocation and self-management and enhanced transaction management.
Support for a wide variety of APIs including ADO, OLE DB, DAO, ESQL, T-SQL and XML.
Ease of integration with the Microsoft Back Office family and Windows NT authentication