OVERVIEW OF MAJOR COMPONENTS - Database Design and Development: An Essential Guide for IT Professionals - page 41

Note the two major groups of people associated with the database environment.
Each group needs a set of procedures. Observe the types of procedures applicable
to each group.

DATABASE AND DBMS

Is Oracle a database? Is Informix a database? Is DB2 a database? Frequently, when
we talk about such commercial products, we tend to imply that these products them-
selves are databases. Someone asks you what database your company uses. You
probably respond by mentioning the name of the commercial product used in your
company.
It is crucial to have a clear understanding of the term database . This topic is about
database design and development. What do we mean by database ? When we discuss
the term database , what is the scope of our discussion? Commercial products such
as Oracle, Informix, and DB2 are not databases per se. They are software products
that support the storage and management of databases. Let us explore the

differences between databases and database software.

DB and DBMS—Not Synonymous

Database Management System (DBMS) is a collection of software components. It
is a set of programs that enables us to create, access, and maintain a database. In
other words, DBMS is a general-purpose software to define databases, build them,
and manipulate the data content. Oracle, Informix, DB2, and similar products are
examples of DBMSs. Database , on the other hand, refers to the data itself. Let us
come up with broad definitions.

Database. Relates to the data and the data structure definitions stored according
to the designed data model with the following features: shared, persistent, secure,
valid, consistent, nonredundant, and independent of application logic.

DBMS. Software that provides services to access and use the database, incorporat-
ing the following features: control of concurrent transactions, recovery from
malfunctions, security against unauthorized data access, reliability in data access,
efficient storage management, and effective language interface for data structure
definition and data access.

Why Use a DBMS?

Consider data management in a file-oriented system. Here, the sequential or
indexed files provide the data content. The applications manipulate the data con-
tained in these files. When you want to list information about a customer in your
organization, you read the particular customer record from the customer sequen-
tial file. Simple file access software and an operating system—just these are all the
software needed for the data access. The same set of software also enables you to
rewrite the updated record or mark outdated records for deletion. Nothing more is
expected from the set of software components for data management.