Thursday, 22 December 2011

Knowing Database

Many of you have heard about database but do you actually know the meaning of database? what is database?how many type of databases? all this i will answer in my blog.. Ok first i will start by introducing what is databases.
DATABASE is  a collection of information that is organized so that it can easily be accessed, managed, and updated. In one view, databases can be classified according to types of content that is:

figure 1:bibliographic

  • bibliographic (a list of writings relating to a given subject)
  • full text
  • numeric
  • image
A database is a structured collection of records or data that is stored in a computer system.

 To be functional: i) Databases must not only store large amounts
                               of records well, but be accessed easily.
                            ii)New information and changes can be easily to
                            iii) All databases that are created should be built 
                               with high integrity and the ability to recover data if hardware fails.

Database Management System(DBMS) - program that manage the queries and information
                                                                                 stored on the system.
Now i will tell you about types of databases.There are many type of databases but i will discuss about the several type of databases in this blog.Each databases have its own model and uniqueness.
They include - Flat Model,
                    -  Hierarchical Model
                    - Relational Model
                    - Network Model

- There is a two dimensional (flat structure) array of data. 
-  A flat model database includes only zip codes. Within the database, there is only one column and
  each new row within that one column will be a new zip code.
figure 2: flat model database
 Hierarchical Model Database
resembles a tree like structure
 each upward link is nested in order to keep data organized in a
   particular order on a same level list.
- example like folder and files.

-A record is stored with a link to other records in effect networked

 most popular type of database and an extremely powerful tool, not 
    only to store information, but to access it as well.
 organized as tables.
Relational databases use a program interface called SQL (Standard Query Language). SQL is currently
  used on practically all relational databases
figure 3: the network model database
easy to customize to fit almost any kind of data storage.
Relations can easily be created for items for sale, employees in a company, etc

figure 4: relational model database

figure 5:hierarchical model database

Thats all for the type of databases.for more understanding about relational type database i will provide a video that will can help you all to understand how the relational type database work.

No comments:

Post a Comment