DATABASE NORMALIZATION

Today every data is stored in a database .so to make it  consistent is important for any database because when data is not consistent it not provide appropriate result to the query .
So here we tell you how to make a table in a ITS NORMAL FORM this process called Database Normalization.

                                        INTRODUCTION

A Database management system is able to achieve its objectives only it has not this two problems:-->>
-->> repitation of data
-->> redudancy of data
Because of this two problems there are several problem arises for example-: inconcistency of data because when a data is repeated saveral places the problem  of updating in database  occurs because the same type data can not equaly updated at a time may be at one of the places the user did any maistake.
TO solve this problem the data stored in RDBMS in table in a normal form .To bring a table in its normal form called (Normalization ).In this process the complex table is divided into some parts and make a relationship among them.
The objective of Database to give the appropriate result to the user .
Here we are going to talk about database Normalization .
For making Database in its Normal form there is need for a language named SQL (strutured query language)here we also discuss about SQL.
OK come Let's see what is Normalization:-
THe  main cause of problems arise in Database is the inconsistency of Database many other problem arise throw this problem.For example Entity (customer's address) stored in three tables ,let the address is changes in future so may be we change the address from two tables but one table may be miss to update in that case the security of database is not safe this type of data cause problem to update.
                     ID           NAME       ADDRESS           ACC_TYPE         ACC_NO.   
                    1101           Ajay            29,K Street             C                       245960
                   1101           Ajay            29,K Street              S                        326221
                   1201          Anil            A-44,RAj Nagar        C                        669245   
                    1201          Anil            A-44,RAj Nagar       S                        23781
                    1201          Anil            A-44,RAj Nagar       F                        55421

IT is the result of a bad table .In this table repitation of data can be seen, we can break this table in two parts:-

ID          NAME          ADDRESS                         ACC_NO.            ACC_TYPE       ID  
1101       Ajay            29,K street                           245960                     C                  1101
1201       Anil             A-44,Raj nagar                     326221                     S                   1101
                                                                              669245                      C                  1201
                                                                              23781                        S                   1201
                                                                              55421                        F                   1201

IT is the example of a simple table.Suppose   are thousands of records so this repitation waste the storage space .

To get rid of this problem.Dr.EF Codd in 1970 give some laws whom we can follow to make a table in its normal form .
After Normalization   some tables are developed which fulfill predefined conditions and rules.
The popular Normal model is :-
First Normal form
Second Normal form
Third Normal form

FUNCTIONAL DEPENDENCY:-
The thought of Normalization is based on  the activities of the functional dependency .
suppose there is R (Relation) table its one attribute (coloum or field) A is dependend on second attribute B functionaly depended on when every value of A is depended only one value of B.

                                         A                      B                           C
                                         a1                      b1                         c1
                                         a2                     b2                          c2                  
                                         a3           b3         c3

In the giaven relation B,functionaly depended on C and C is functionaly depended on B because the value of B is related with C's only one value.

                                            C                    F.D                on      B                                            B                     F.D                on      C

Now we can see the attribute A and B the A is not functionaly depended on B because the one value of A related with  two  value of B b1 b2.

                                                              a1
                     a1   >>>>>>>>>>>>>|
                                                                b2 

In this case if user wants to see the records related to   a1    he has to face a condition of confusion   that which record is right record a1 , b1 ,or a2,b2    If we see the dependency  between B and A so we saw that A is depended on B because every value of B is related to A.
                                        b1--------->>a1
                                        b2-------->>a1

In this case if user wants to see the record of B he is not confused at all.
1NF FIRST NORMAL FORM:=>>
A Table is called in first normal form when it has only one value in a field .
                    ROLL_NO.                NAME          SUBJECT        MARKS
                       1101                        AMIT                 MATHS    90
                                              PHYSICS          78  
                                                                              COMPUTER 84  
                       1102       RITU              MATHS              90 
                             PHYSICS             61 
                            COMPUTER  75 
                                                 

                                                       IS A ORDINARY TABLE 

ROLL_NO.               NAME         SUBJECT               MARKS
1101    AMIT         MATHS         90
1101   AMIT  PHYSICS               78
1101   AMIT  COMPUTER         84
1102   RITU     MATHS         90
1102 RITU     PHYSICS 61
1102 RITU   COMPUTER         75  
THE above table is in first normal form

II ND  (SECOND NORMAL FORM)
A Table called in second normal form when it is in first normal form and its every atrribute is fully depended on the table's primary key (pk) .suppose AB is the composite primary key if tables other attribute column C and D then C and D should be  functionaly depended on AB. If C and D is functionaly depended on A and B so this table is not in second normal form.

STU_CODE                       STUDENTS CODE                                                  
PROJ_CODE                      PROJECT CODE                                                    
LANGUAGE                       WHICH LANGUAGE USED IN PROGRAMING  
INSTRUCTER_ID              FACULTY OF THE PROJECT                                
DURATION                        TIME FOR SUBMISSION OF PROJECT              

THE GIVEN SCHEMA TABLE IS SOMETHING LIKE THIS:=

                                PROJECT

STU_COD     PRO_COD           LANGUAGE         INSTRUCTER ID         DURATION
101                  P11                       C++                       I-1                                  7
102                  P9                         JAVA                    I-2                                  6
405                  P11                       RDBMS                I-4                                 15    
209                   P9                        VC++                   I-3                                 10 
209                   P13                      VC++                   I-3                                  12            
102                   P13                      JAVA                   I-2                                   15  
This project's composit key (stu_code+pro_code) is its primary key during the activity of this database here are some of the problems face :=>> 

• The record of a student can't be stored whose instructer is not declared .
• One student data is repeated at many times.
• one pro_code and stu_code is repeated at many times.
• If one stu_code is changed it is difficult to update the table.

To solve this tables errors :
Taken out the records which is depended only one value of table (stu_code or pro_code).
And let the table as it is after removing the records point out above so we can got our IInd normal table

student table

STU_COD                LANGUAGE         INSTRUCTER ID  
101                                    C++                     I-1                   
102                                   JAVA                   I-2                  
405                                   RDBMS                I-4                
209                                   VC++                   I-3               
209                                   VC++                   I-3             
102                                   JAVA                   I-2            

                                                 project Table

STU_COD     PRO_COD     DURATION

101                  P11                                  7

102                  P9                                    6

405                  P11                               15 

209                   P9                                10 

209                   P13                              12 

102                   P13                              15 

 IIIrd Normal Form :-

In second normal form we see the dependency of the table's primary key to other   attributes.In the IIIrd Normal Form we discuss further and we saw the other attributes  dependency as well as pk.

A table is in its third normal form  when its all non primary key attribute is functionaly depended on primary key attribute .

                     Every III    Normal form table should be in IInd Normal Form and Ist Normal form    :-

STU_COD                LANGUAGE         INSTRUCTER ID  
101                                    C++                     I-1                   
102                                   JAVA                   I-2                  
405                                   RDBMS                I-4                
209                                   VC++                   I-3               
209                                   VC++                   I-3             
102                                   JAVA                   I-2            

When we look at the above table we can see that attribute language and Instructer Id is depended on each other because only one value is related to anothers one value.

                                                       

                               C++----->>I-1

                               java------>>I-2

                               VC++---->>I-3

                               RDBMS----->>I-4

SO IT IS NOT A IIIrd NORMAL FORM OF THE TABLE.

HERE WE GOING TO PRESENT THE IIIrd NORMAL FORM OF A TABLE:=>>

STU_COD                LANGUAGE         
101                                    C++              
102                                   JAVA            
405                                   RDBMS        
209                                   VC++          
209                                   VC++         
102                                   JAVA        

        LANGUAGE         INSTRUCTER ID  

       C++                     I-1                   

       JAVA                   I-2                  

       RDBMS                I-4                

       VC++                   I-3               

       VC++                   I-3             

       JAVA                   I-2            

THE ABOVE TABLE IS IN IIIrd NORMAL FORM 

      

Here every value is functionaly depended on primary key.  

.

                       

system analysis and design

System are created to solve problems.One can think of the systems approach as an organised way  of dealing with a problem. In this dynamic world ,the the subject system analysis and design ,mainly deals with the software development activities.

System

A collection of components that work together to realize objective forms of a system .

Basically there are three major component in every system ,namely Input,processing and output .

INPUT--->[PROCESSING]------>OUTPUT

In a system ,the different components are connected with each other and they are interdependent . e.g.,human nbody represents a complete natural system .we are also bound by stystem .

System  Life Cycle 

System life cycle is an organisational process of developing and maintaining a system .

It helps in estabilishing a system project plan, because it gives overall list of processes and sub processes required  developing a system .

In other words, we can say that various activities put together are referred as system development life cycle.

In this analysis and design terminology ,the system development life cycle means software development life cycle.

Following are the different phases of software development cycle

• System study
•  Feasibility study
•  System analysis
•  Coding
•  Testing    
•  Implementing
• Maintenance

             The different phases of SDLC (software development life cycle)

         ------  >>                    System Study            <<--------
        |                                                                                     |
Maintainance                                                               Fasibility Study
        |                                                                                     |
Implementation               Software devlopment             System Analysis
        |                                                                                     |
  Testing                                                                         System Design
                                           LIFE   Cycle                          
       
          ------>>                       Coding                      <<--------  

                                         

                   Different Phases of Software Development Life Cycle                                                              

      

MODERN INDIA

ADVENT OF EUROPEANS

Portguese

Vasco de Gama- reched the port of calicut in 1948 during the reign of king Zamorin .(Hindu ruler of calicut).

Alfonso de Albuquerque-the second governer of India (First being fransisco de almeida) arrived in 1509and captured Goa in AD 1510.

Settlements- Daman,Salsette,Chaul and Bombay(West coast),San Thome(near Madras)and at Hoogley.

Dutch

Dutch East India Comapny was formed in AD 1602.

Dutch was defeated by English at the Battle Of Bedera in AD 1759  and as per agreement ,the Dutch gained the control over  indonesiaand the british over India,Sri Lanka and Malaya.

Settlements  They setup their first factory  at masulipatnam in 1605.their other factories were pulicat ,chinsura ,patana,Balasore,Nagapattanam,Cochin,Surat,Karikal,Kasmibazar.

English

The English East Indai Company was formed in 1599 under a charter granted by Elizabeth in 1600.

Jahangir granted a farman to Captain William Hawkins permitting the English to erect a factory at Surat (1613).In  1615 Sir THomas Roe succeeded in getting an imperial farman to trade and establish factory in all parts of the Mughal Empire by ruler Jahangir.

Battle of Plassey- (1757)English defeated Sirajuddaula ,the nawab of Bengal.

Bettle of Buxar-(1764) Captain munro defeated the joint forces of mir Qasim (Bengal), shujauddaula(awadh)and Shah Alam II (Mughal).

Danes 

The Danish East India Company was formed in 1616.

Settlements serampur (Bengal),and tranquebar (Tamil Nadu) sold their settlement to the English in 1845.

French

The French East India Company was formed by colbert uneder state patronage in 1664. The First French factory was established at surat by francois caron in 1668. A factory at  Masulipatanam was set up in 1669.

 French were defeated by English in Battle Of Wandiwash (1760) .