What is database?
A
database is a collection of related data stored in an efficient
and compact manner. The word “efficient” means
that stored data can be accessed very easily and quickly.
Similarly,
the word “compact” means that stored data takes up as
little space as possible. In the above definition of database,
the phrase “related data’ is used. It means that a database
contains data or information about a particular topic such
as:
A database holds related data as
well as description of that data. For this reason, a database
is also defined as a self describing collection of integrated
records. The description of data is known as the system
catalog or data dictionary or metadata. For example when
a table of a database is designed, the data type, size,
format and other descriptions of fields are specified. This
is an example of metadata, which describes the properties
of data to be stored into fields of table.
The data of any organization is
its integral part. The data is very important for developing
new products and their marketing. The data must be accurate
and available when needed. This is the reason that all organization
must organize and manage their data into database. The databases
are used for variety of purposes in as organization. For
example, when you purchase goods from your local supermarket,
the checkout assistant will pass the purchased product through
a scanner device known as bar code reader. This device will
read the bar code printed on the product and gives the accurate
price of the item. Actually, the bar code reader is
accessing the database, which contains the information about
the products. The bar code reader is linked to a database
application program, which uses the bar code to access price
of item. The database program automatically updates the
database. The assistant can also check whether a required
item is in stock by running the database application program.
Similarly, you can purchase goods using your credit card.
Your credit is checked by a card reader linked to a computer
system. In this case, there is a database somewhere that
contains information about your credit. Almost all organizations
and government departments of every country in world use
database to maintain their records. Some examples of large
databases that have been developed around the world are:
-
When you draw amount from bank
through ATM card, you are accessing the database; your
account is accessed and checked through auto teller
machine. When you draw some amount from your account,
your record in the database is automatically updated
immediately.
-
When you visit your local library,
there may be a computerized database containing details
of the books in the library. There will be a computerized
index, which allows you to find a book based on its
title, its author’s name etc.
-
The meteorological organization
contains databases having information about current
and previous meteorological data. The meteorological
department is totally dependent on the meteorological
data.
A database may be generated and
maintained manually or it may be computerized. The library
card catalog is an example of a database that is created
and maintained manually. On the other hand, a computerized
database may be created and maintained either by using application
program, which is developed specifically for that purpose
or by a database management systems.
