Database Reference
In-Depth Information
the code for application logic executes on the client machine or on a separate appli-
cation server.
Reduced Program Maintenance
This benefit of database systems results pri-
marily from data independence in applications. If the customer data structure
changes by the addition of a field for cellular phone numbers, then this change is
made in only one place within the database itself. Only those programs that need
the new field need to be modified and recompiled to make use of the added piece
of data. Within limits, you can change programs or data independently.
Simpler Backup and Recovery
In a database system, generally all data are in
one place. Therefore, it becomes easy to establish procedures to back up data. All
the relationships among the data structures are also in one place. The arrangement
of data in database systems makes it easier not only for backing up the data but
also for initiating procedures for recovery of data lost because of malfunctions.
THE DATABASE APPROACH
What are the implications when an organization makes the transition from file-
oriented systems to database systems? When an organization changes its approach
to management of data and adopts database technology, what are the significant
effects in the way business is conducted? What happens when an organization
embraces the database approach?
Let us find answers to such questions. We will discuss the way applications are
designed and implemented with database systems. We will explore the basic con-
cepts of the database approach. We will also review some of the types of databases
and how these are used.
We have reviewed the benefits of database systems and established how they are
superior to the earlier file-oriented data systems. We caught a glimpse of the fea-
tures of database systems that produce several benefits. Database systems reduce
data redundancy, integrate corporate data, and enable information sharing among
the various groups in the organization. Now you are ready for an initial, formal def-
inition of a database.
Database: A Formal Definition
Let us examine the following definition:
A database is an
ordered collection
of
related data elements
intended to meet
the infor-
mation needs
of an organization and designed to be
shared
by multiple users.
Note the key terms in the definition:
Ordered collection.
A database is a collection of data elements. Not just a random
assembly of data structures, but a collection of data elements put together deliber-
ately with proper order. The various data elements are linked together in the most
logical manner.
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