Type 1 Slowly Changing Dimension

In Type 1 Slowly Changing Dimension, the new information simply overwrites the original information. In other words, no history is kept.

In our example, recall we originally have the following table:

Customer Key	Name	State
1001	Guru	Jharkhand

After Guru moved from Jharkhand to Karnataka, the new information replaces the new record, and we have the following table:

Customer Key	Name	State
1001	Guru	Karnataka

Advantages:

- This is the easiest way to handle the Slowly Changing Dimension problem, since there is no need to keep track of the old information.

Disadvantages:

- All history is lost. By applying this methodology, it is not possible to trace back in history. For example, in this case, the company would not be able to know that Christina lived in Illinois before. 

When to use Type 1:

Type 1 slowly changing dimension should be used when it is not necessary for the data warehouse to keep track of historical changes.