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Unit 8: Normalization
If there are such groups in the table, the table should be decomposed and the associated columns Notes
will form their own table while at the same time ensuring a link of this table with the original
table (from where it was decomposed). Thus, the Employee relation can be divided into two
relations namely Emp and Emp_Depend as follows:
Emp
ID Name DeptNo Sal Mgr
131 Ram 20 10000 134
132 Kiran 20 7000 136
133 Rajesh 20 5000 136
134 Padma 10 20000
135 Devi 30 3000 137
136 Satish 20 6000
137 V.V. Rao 30 10000
Emp_Depend
S. No. ID Dependents
1 131 Father
2 131 Mother
3 131 Sister
4 132 Wife
5 132 Son
6 133 Wife
7 134 Son
8 134 Daughter
9 135 Father
10 135 Mother
11 136 Father
12 137 Wife
13 137 First Son
14 137 Second Son
Notes The SNo column is added in the Emp_Depend table because according to relational
model, every table must have a unique identifier. In this table, ID cannot serve as a unique
identifier and hence introduced SNo as primary key.
After first normal form, this table is divided into two tables: Customer and Customer Tran.
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