In SCD type 3, a new column is added to the orginal data, which displays the partial historical data
Let us consider the example:
EmpNo Name Location
1001 Mark Delhi
Consider Mark moves from Delhi to Manchester, then a new column is added to the previous data as shown below
EmpNo Name CurrentLocation PreviousLocation
1001 Mark Manchester Delhi
Consider Mark moves again from Manchester to Dublin then you have
EmpNo Name CurrentLocation PreviousLocation
1001 Mark Dublin Manchester
So, SCD type 3 maintains partial history
Advantages:
It maintains partial history and with this size of the table doesn't increase as much as it does in SCD type 2
Disadvantages:
The organisation doesn't have complete information the employee as it cannot track the complete history of the employee i.e., from the above example when Mark moves to Dublin the organisation doesn't have any trace of his working in Delhi.
Note: SCD type 3 maintains Current data + partial history
Let us consider the example:
EmpNo Name Location
1001 Mark Delhi
Consider Mark moves from Delhi to Manchester, then a new column is added to the previous data as shown below
EmpNo Name CurrentLocation PreviousLocation
1001 Mark Manchester Delhi
Consider Mark moves again from Manchester to Dublin then you have
EmpNo Name CurrentLocation PreviousLocation
1001 Mark Dublin Manchester
So, SCD type 3 maintains partial history
Advantages:
It maintains partial history and with this size of the table doesn't increase as much as it does in SCD type 2
Disadvantages:
The organisation doesn't have complete information the employee as it cannot track the complete history of the employee i.e., from the above example when Mark moves to Dublin the organisation doesn't have any trace of his working in Delhi.
Note: SCD type 3 maintains Current data + partial history
