OVERVIEW OF MAJOR COMPONENTS - Database Design and Development: An Essential Guide for IT Professionals - page 37

So, in this new environment providing database functions, you require robust data
storage mechanisms. The operating system alone cannot support data retrieval and
presentation. Simple methods of data backup and recovery are not adequate.
Complex data structures have to be properly defined. Data delivery systems must
be properly tuned to provide instant data access and retrieval. The environment
must be open to hundreds or thousands of users. It should be able to handle con-
current transactions seeking to access the same pieces of data and still ensure the
integrity of the data. Powerful processors, robust data repository, enhanced operat-
ing systems, improved networking capabilities, specialized database software—all of
these become necessary components of the database environment.
We have mentioned just the software and hardware components necessary in the
database environment. Software and hardware components, however important
they may be, are not enough to make the database work. We need the people com-
ponents. We need procedures for people to carry out the various functions. Who are
these people? Users on one hand and database practitioners with special skills on
the other hand. The database environment, therefore, also consists of people and
procedures. Let us look at the overall architecture of the database environment and
then discuss each component in sufficient detail.
Overall Architecture
How do you determine the architecture of a building? You look at the building
blocks. You notice the arrangement of the components in the structure. These build-
ing blocks, together with their arrangement, make up the overall architecture of the
building. Similarly, what is the overall architecture of a database environment? What
are the pieces that make up the architecture? How are they put together and
arranged to become a cohesive whole?
Essentially, a database environment includes the storage of data. The data
repository, important as it is, constitutes just one piece in the overall architecture.
You need specialized software to manage and make use of the data. You need hard-
ware to store and process the data. You already know about the people component.
You are also aware of the procedures necessary to guide the storage, management,
and use of data. Figure 2-2 illustrates the overall architecture of a database envi-
ronment in an organization. Note the individual components and observe how they
are connected.
Before we discuss hardware, software, and people in detail, let us quickly go over
the functions of the individual components as seen in Figure 2-2.
Data repository. Stores the organization's data in databases. This is a primary
component, essential in every database environment.
Data dictionary. Contains the definition of structures of the data stored in the data
repository. As mentioned previously, keeping the structure definitions apart from
the actual data provides a level of independence in the database environment.
DBMS. Database Management System is specialized software needed to manage
storage, use, and protection of the data stored in the database.