What are the dimensions measure and fact table?
Dimension table. In data warehousing, a dimension table is one of the set of companion tables to a fact table. The fact table contains business facts (or measures), and foreign keys which refer to candidate keys (normally primary keys) in the dimension tables.
What is an accumulating snapshot fact table?
Accumulating Fact tables are used to show the activity of progress through a well-defined business process and are most often used to research the time between milestones. These fact tables are updated as the business process unfolds and each milestone is completed.
Can fact table have dimensions?
Collection of reference information about a business. Facts tables could contain information like sales against a set of dimensions like Product and Date. Evert dimension table contains attributes which describe the details of the dimension.
What are two types of facts?
Types of Facts
- Additive: Additive facts are facts that can be summed up through all of the dimensions in the fact table.
- Semi-Additive: Semi-additive facts are facts that can be summed up for some of the dimensions in the fact table, but not the others.
How do you identify dimensions?
To identify dimensions, you perform the following steps:
- Use the grain definition to locate possible dimensions.
- List all of the dimensions that are associated with this grain. Define the level of detail to include in that dimension.
- Create surrogate keys for the primary keys of the dimensions.
What can you use instead of an accumulating snapshot fact table?
There are other options you could use instead of an accumulating snapshot fact table to capture this information. You could track this information as a type 2 SCD for claim. In this instance, you would add milestone to the claim dimension and track the information using the active dates of the dimension.
When is an accumulating fact table row inserted?
An individual row in an accumulating snapshot fact table, corresponding for instance to a line on an order, is initially inserted when the order line is created. As pipeline progress occurs, the accumulating fact table row is revisited and updated.
Which is bigger a time stamped snapshot or an accumulating snapshot?
If an average claim is changed on twenty days during its life, the time stamped snapshot will be twenty times bigger than the standard accumulating snapshot. Take a look at your data and your business’s requirements to see if it makes sense for you.
What can be modeled with a fact table?
Pipeline or workflow processes, such as order fulfillment or claim processing, that have a defined start point, standard intermediate steps, and defined end point can be modeled with this type of fact table. There is a date foreign key in the fact table for each critical milestone in the process.