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data mapping is used to map complex data into a single value

the idea is if an object has complet data to process, like (object, value1, value2, value3,value4....), we can mapping (object, value1, value2, value3,value4....) into a single value X, then we process only X to make it faster

here is an use case:

we have two 2D data arrays with 5 columns, the first column is the name of object, the other fours are the differents value of this object

Data ArrayA:

object	value1	value2	value3	value4
X	1	2	3	4
Y	5	6	7	8
Z	9	10	11	12

Data ArrayB:

object	value1	value2	value3	value4
X	1	2	3	4
Y	5	8	7	8
Z	9	10	192	12

now we need to compare data array A to data array B to find which object inside A has different value.

without data mapping, we need to compare each object's 4 values, the complexity is O(2^n)

with data mapping:

we map those values:

(X, 1, 2, 3, 4) ==> 1

(Y, 5, 6, 7, 8) ==> 2

(Z, 9, 10, 11,12) ==>3

(Y, 5, 8, 7, 8) ==> 4

(Z, 9, 10, 192, 12) ==> 5

Data ArrayA:

object
1
2
3

Data ArrayB:

object
1
4
5

then compare 1D array is fast, the complexity is O(n)