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Content
 What is Data
 What is Database???
 DBMS
 Uses
 ER-Diagram
 Purpose of Dbms
 Dbms Architecture
 Advantages
 Disadvantages
What is data
Database is an organized collection of data.
The data is typically organized to model aspects of
reality in a way that supports processes requiring
information. For example, modeling the availability
of rooms in hotels in a way that supports finding a
hotel with vacancies.
What is Database???
A database is an
organized collection of
data. The data is typically
organized to model
aspects of reality in a way
that supports processes
requiring information. For
example, modeling the
availability of rooms in
hotels in a way that
supports finding a hotel
with vacancies.
Database Management System
• A database management system (DBMS)
is a collection of programs that enables
you to store, modify, and extract
information from a database. There are
many different types of DBMSs, ranging
from small systems that run on personal
computers to huge systems that run
on mainframes.
• The following are examples of database
applications:
• Computerized library systems
• Automated teller machines
• Flight reservation systems
• Computerized parts inventory systems
ENTITY RELATIONSHIP
DIAGRAM
• The most important consideration is
designing the database is how the
information will be used. The various
application and procedures that will be
used in the database introduce the
requirements upon the structure of data.
• In relational database, representation of
data and data relationship is a collection of
tables.
. Each table has one or more columns.
The first step in creating a database is
designing it. First plan is what are the tables
that we require and the type of data it will
contain. It also determines how the tables are
related. That is a very important step and
deserves careful consideration.
It should determine the things we want to store
as information and how are they related.
A useful technique in designing the database is
to draw a diagram of the tables. This graphical
display of database is called an Entity
Relationship Diagram (E.R Diagram).
SOME EXAMPLE OF DBMS
ON FRONTEND
Advantages of Dbms
One of the main advantages of using a
database system is that the
organization can exert, via
the DBA, centralized
management and control
over the data. The database
administrator is the focus of the centralized
control.
• Reduction of Redundancies: Centralized
control of data by the DBA avoids unnecessary
duplication of data and effectively reduces the
total amount of data storage required. It also
eliminates the extra processing necessary to
trace the required data in a large mass of data.
Elimination of Inconsistencies: Any
redundancies that exist in the DBMS are
controlled and the system ensures that
these multiple copies are consistent.
Security: Data is of vital importance to an
organization and may be confidential. Such
confidential data must not be accessed by
unauthorized persons.
Cost of software/hardware and migration:
A significant disadvantage of the DBMS
system is cost. In addition to the cost of
purchasing or developing the software, the
hardware has to be upgraded to allow for
the extensive programs and work spaces
required for their execution and storage.
Problem associated with centralization:
While centralization reduces duplication, the
lack of duplication requires that the
database be adequately
backed up so that in the case of failure the
data can be recovered. Centralization also
means that the data is accessible from a
single source. This increases the potential
severity of security breaches and disruption
of the operation of the organization because
of downtimes and failures.
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