A database is an organized collection of facts.
example of database is collection of students record, collection of blog posts, collection of images.
Fundamental of records
When we place data of any object in the form of properties is called record
for example we want to store data for the person like
- gender, etc
Column containg data in a table is called field.
like name, mobile, gender, email, password, etc.
Collection of related fields in a table is called record.
Collection of related records is called the file.
Collection of related files is called the database.
If more than one table has a common field is called key field.
As you can see posts table has a column user_id that belongs to the users table is called the key field.
DBMS (Database management system)
It is a software package that allows data to be effectively stored, retrieved and manipulated.
some common popular DBMS examples are MS Access, SQL Server, Oracle, MYSQL etc.
Data are raw facts that can be manipulated.
Processed form of data is called the information.
There are three stages for data processing
- Capturing data from the source.
- Store the data
- Update and retrieve the data in the form of information.
Data managemenet is the arrangement of all the data and information where we define.
Standards for the defining data like how the data will store
Define the way how different users will use the data.
Data independence allows a database to be changed dynamically.
We can add the data
we can change the structure of schema like
- alter columns
- delete columns
- add new columns
Types of DBMS users.
There are four types of DBMS users.
- Naive users(End users)
- Online users
- Application programmers
Naive users(End users)
Now days naive users are called end users, end users has very limited access to the database as programmer define at the time of development of system.
For example, who is using facebook to create new profile, add new post and like the post are called the end users.
Online users use the database using computer terminal and they has some basic knowledge about the structure of database
These users develop the system and connect the system with the database.
These users has complete information about the database like what is the structure of database and how it is formed and how is managing and also know about the system of Current DBMS.
A data model is a description of the organization of a database.
description of the organization means how data organized in the database.
Data models are categorized into three parts.
- File based data models
- Traditional data models
- Semantic data models
File baesd data models
In file based data models records are store in the file.
Traditional data models
Traditional data models categorised into three parts
Semantic data models
File or traditional based system are used to store the data whereas semantic data models are used to store knowledge that is done by the researchers or artificial intelligence machines.
Characteristics of a DBMS.
- Create relationship between different data
- Control the data redundancy
- Ensure data can be shared across all the applications
- Enforce data access authorization
- Allow automatic and intelligent data backup
- Has different interface to access and manipulate the data.