The Evolution of Database Development Oracle Tips by Burleson Consulting

The Data Warehouse Development Life Cycle

The Evolution of Database Development   

Even with centralized databases, users still faced the problem of diverse data platforms. Many companies embarked on "downsizing" or "rightsizing" their system to take advantage of cheaper processing on minicomputers and PC platforms. In the process, many users abandoned the idea of a central repository of data and attempted to build "bridges" between the applications. Unfortunately, these bridges were often quite complex and difficult to manage. For example, establishing communications between a PC relational database and a CODASYL mainframe database is very cumbersome.

Many companies found that frequent reorganizations and corporate acquisitions led to many diverse platforms for their information. Most large companies have many different database management systems and perhaps dozens of hardware platforms. These market conditions have led many information systems managers to develop systems in a reactive mode, focusing on the immediate need for these systems to communicate, rather than on a common, centralized access method.

In the 1980s, IBM introduced the concept of enterprise modeling, whereby the entire organization’s information was modeled, and the overall system was composed of a large client/server environment. This model was based on the idea that data should become independent of its source and that information can be accessed regardless of the type of database manager and hardware platform.

Today, many companies adopt the posture that their systems should exploit the "right" database systems, and it is acceptable to have many different database systems on many different platforms. A relational database, for example, is ideal for a marketing system, while an object-oriented database is well-suited for a CAD system.

Friendly application interfaces also helped to foster downsizing. As end-users were exposed to windowing systems on PC networks, they began to view the block-mode systems on the mainframe as unacceptable and began to be more demanding on the information systems staff to produce friendlier and more intuitive systems.

The goal of a centralized data repository could never materialize, especially for dynamic companies. Acquisitions of new companies, mergers, and reorganizations helped to ensure that managers always faced diverse information systems. Ironically, the reason for many acquisitions was to take advantage of the synergy that would materialize from the sharing of information. Consequently, information systems managers became the agents of achieving this synergy, and they faced complex problems associated with establishing communications among diverse platforms.

---

This is an excerpt from "High Performance Data Warehousing", copyright 1997.

If you like Oracle tuning, you may enjoy the book Oracle Tuning: The Definitive Reference , with over 900 pages of BC's favorite tuning tips & scripts.  You can buy it directly from the publisher and save 30%, and get instant access to the code depot of Oracle tuning scripts.