What is data ?
Data is a collection
of a distinct small unit if information. it can be used in a verity of forms
like text, numbers, media, bytes etc. It can be stored in pieces of paper or
electronic memory etc.
Word
'Data' is Originated from the word 'datum' that means 'single piece of
information' . It is plural of the word datum.
In computing , Data
is Information that can be translated into a form for efficient movement and
processing. Data is interchangeable.
What is Database ?
Database is an organized
collection of data that can be easily stored, Accessed and managed . we can
also say a database is a data structure that stores organized information.
You can Organize data
into tables, Rows, Columns, and index it to make it easier to find relevant
information.
For an example, a
company database may include tables for products, employees and Financial
records.Each of these tables would have different fields that are relevant to
the information stored in the table.
There are many
Databases available like MySQL, Sybase, Oracle, MongoDB, Informix, PostgreSQL,
SQL server etc.
What Is DBMS
(Database Management System) ?
A Database management
system (DBMS) is system software for Creating and Managing Database. A DBMS
makes it possible for end users to create,read, update and delete data in a
database. The DBMS essentially severs as an interface between database and end
users or applications programs, ensuring that data is consistently organized
and remains easily accessible.
Database Management
system also aims to facilitate an overview of the database, by providing a
verity of administrative operation such as tuning, performance monitoring and
backup Recovery.
Database
management systems allow users to do the following:
- Define Data – Allows the users to create, modify and delete the definitions which define the organization of the database.
- Update Data – Provides access to the users to insert, modify and delete data from the database.
- Retrieve Data – Allows the users to retrieve data from the database based on the requirement.
- Administration of users – Registers the users and monitors their action, enforces data security, maintains data integrity, monitors performance and deals with concurrency control.
Evolution
of Database
The
Database has completed more than 50 years of Journey of its evolution from
flat-file system to relational and objects relational system.
The
Evolution (Types of DBMS)
Flat
File:
1968 was the year when File-Based Database were introduced. In File-Based Databases, data was maintained in a flat file. Though files have many advantage, there are several limitations.
One
of the major advantage is that the file system has various access methods.
e.g. Sequential, indexed, and random.
It
requires Extensive programming in a third-generation language such as
COBOL,BASIC.
Hierarchical
Database Model:
1968-1980
was the era of the Hierarchical database. Prominent hierarchical database model
was IBM's First DBMS. It was Called IMS (Information Management System)
Below
Diagram Represents Hierarchical data Model. Small Circle Represents Objects.
Network Database
Model:
Charles Bachman
developed the first DBMS at Honeywell called Integrated Data store (IDS). It
Was Developed in the early 1960s, But it was Standardized in 1971 by the
CODASYL group (Conference on Data System Language)
In
this model, Files are related as owners and members, like to the common network
model.
Network
Data Model Identified the Fallowing components:
- Network schema (Database organization)
- Sub-schema (views of database per user)
- Data management language (Procedural)
This
Model also had some limitations like system complexity and difficult to design
and maintain.
Relational
Database model:
1970-Present: It is the era of
Relational Database and database management. In 1970, the Relational model was
proposed by E.F. Codd.
It
can be defined using two relationship:
Instance
: A table with rows and columns.
Schema
: specifies the structure (Name if relation, Name and type of each column)
Relational
Database Properties
- Atomicity
- Consistency
- Integrity
- Durability
Advantage:
Ease
of use because of ROWS and COLUMNS.
Flexibility
with respect to manipulation by operators such as project and join.
Precision
sue to the manipulation of the relations between the tables ensures that there
is not ambiguity.
Disadvantage:
Machine
Performance in case of large number of joins.
Physical
Storage consumption.
Slow
Extraction of data.
The Object-Oriented Databases:
The object-oriented databases contains data in the form of object and Classes. Objects are the real world entity, and types are the collection of Object. An Object-Oriented database is a combination of relational model features with object oriented principles. It is an alternative implementation to that of the relational model.
Object-oriented Database model contains the fallowing properties.
- Objects
- Classes
- Inheritance
- Polymorphism
- Encapsulations
Thank you !! I Hope you will find this article informative.
