• Xiaowu Zhang's avatar
    erp5_wendelin: add data mapping · ed280d8d
    Xiaowu Zhang authored
    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)
    ed280d8d
document.erp5.DataMapping.xml 3.23 KB