A measure is a numerical property of a fact and describes a quantitative aspect of a fact that is relevant to analysis. |
For example, each sale is measured by the number of units sold, the unit price, and the total receipts.
The reason why measures must preferably be numeric is that they are generally used to make calculations.
A fact can also have no measures, when users are interested in recording only the occurrence of an event; in this case, the fact schema is said to be empty.
In the DFM, the measures of a fact are listed below the fact name.
