Till now, we have already discussed about types of dimension. So lets move to another concept in dimensional modelling, i.e, FACT . A fact is a measure or metrics of business process. In simple words, a fact is a focus of interest for the decision making process. Facts are summarized historical and numerical data.
Types Of Fact :
Basically , there are three types of fact :
- Additive Facts
- Semi-Additive Facts
- Non Additive Facts
1. Additive facts :
The most flexible and useful facts are additive facts.Additive facts are those specific class of fact measures which can be aggregated across all dimension and their hierarchy
For e.g : lets consider sales figures…one may tend to add sales across all quareters to avail the yearly sales..hence this is an example of Additive measure
2. Semi-Additive Facts:
These are those specific class of fact measures which can be aggregated across all dimension and their hierarchy except the time dimension
For e.g – Daily balances fact can be summed up through the customers dimension but not through the time dimension.
3. Non Additive Facts :
These are those specific class of fact measures which cannot be aggreagated across all/any dimension and their hierarchy
For e.g – Aggregation of percentage or dates is an Ideal example of non-additive measures.