Database Reference
In-Depth Information
MAJOR DEVELOPMENT STEPS
For a moment, think of an organization running its business with file-oriented
systems. All the data that support the business reside on sequential or flat files. There
is no flexibility, no data sharing. Each user group has its own set of files; you note
data proliferation to a great extent. You find disparate islands of data—all of which
are meant to support one core business of the organization. The same elements of
data may be found in different files, and these duplicate versions of the same data
elements could result in gross data inconsistency.
Now imagine the same organization running its business with a database system.
This environment is quite the opposite of one with file-oriented systems. First, you
observe data integration with completely reduced data duplication. Removal of data
redundancies produces a major improvement and projects a uniform image of the
company to the outside world. Every document sent to customers and business
partners shows the same values for any data element.
Information sharing resulting from a database system is a major change in the
organization. Users are no longer confined to their own individual sets of files. Each
group of users does not try to protect its data turf. Data in the database system are
everyone's data; the integrated whole is for the benefit of the entire organization;
the data serve the core business of the organization as a single entity. The transi-
tion of an organization from data proliferation to information sharing constitutes a
major step.
So how does the changeover from individual data files to an integrated database
system occur in an organization? How does the transition from an environment of
isolated data islands to one of information sharing happen? With a lot of planning,
of course. Companies need to plan and think through all the aspects of the change.
The transition requires a systematic and coordinated effort. The development of a
database system calls for a proven approach with distinct and purposeful steps. Busi-
nesses adopt a life cycle approach to database development. In a life cycle approach,
you pay attention to each individual step and make the steps proceed in a standard,
productive manner. The approach deals with all the necessary steps in the life of a
database system from beginning to ongoing phases.
Starting the Process
Let us go back to when data systems and applications were developed in a file-
oriented environment. Consider developing applications for the order processing
department in an organization. You study the various functions performed for com-
pleting the processing of orders. You gather the data required to complete each task
of these functions. Then you put all the required data into one or more sequential
files, and these files make up the data system for the department. Here you use a
function-oriented approach to developing the data system. In a function-oriented
approach, the focus is on the functions. If the functions change or if you need to
add more functions, the composition of the data system changes too, sometimes
quite extensively.
However, it is different in a database system. This type of data system is designed
to cater to current information needs and be able to extend easily to accommodate
changes in the requirements and to meet additional ones. You do not focus on the
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