Dimension and Fact

Whether implementing a dashboard or data warehouse there are some common concepts such as fact and dimension which we must first understand.

• First let’s take a look at the dimension
  • Dimension contains information about a business.
  • Basically, any information that answers the questions what, where, how, who, and when is Dimension.

For example, the employee or customer could both answer the question of who or the branch could answer the question of where and Today could answer the question of when and so on.

and now about the fact

• The fact table includes numerical values of what we measure.
• It contains facts, measurements, and metrics of a business process.
• In reality, anything that shows how much or how many is called a measure.
• The data stored in a fact table is often numerical.
• It also acts as a foreign key to dimensional tables.

what is the difference between metric and measure? a measure is a simple number, such as, how many miles you traveled, a metric puts that measure into context – how many miles you traveled per hour

• This illustration is called star schema where fact is in the center and dimensions are around it.

It is worth noting that dimensions do not have sub-dimensions which tells us this is not a snowflake schema. You can observe how the sales fact is in direct relation to the item, branch, time, and location dimensions. Sales fact measures quantity, amount, and the average of sales.