What is a factless fact and when would you use it give examples?
They are often used to record events or coverage information. Common examples of factless fact tables include: Identifying product promotion events (to determine promoted products that didn’t sell) Tracking student attendance or registration events.
What is factless fact in data warehouse?
Data Warehousing > Concepts > Factless Fact Table. A factless fact table is a fact table that does not have any measures. It is essentially an intersection of dimensions. On the surface, a factless fact table does not make sense, since a fact table is, after all, about facts.
What is the purpose of a dimensional model?
The purpose of dimensional modeling is to enable business intelligence (BI) reporting, query, and analysis. The key concepts in dimensional modeling are facts, dimensions, and attributes. There are different types of facts (additive, semiadditive, and nonadditive), depending on whether they can be added together.
What are Factless facts in Microstrategy?
A factless fact table is table that doesn’t have fact at all. They may consist of nothing but keys. There are tow types of factless fact table.
What are Factless facts?
Factless facts are those fact tables that have no measures associated with the transaction. Factless facts are a simple collection of dimensional keys which define the transactions or describing condition for the time period of the fact.
Where is factless fact table used?
It is used to support negative analysis reports. For example, a store that did not sell a product for a given period. To produce such a report, you need to have a factless fact table to capture all the possible combinations of products that were on sale.
What are factless fact tables used for?
Factless fact tables are only used to establish relationships between elements of different dimensions. And are also useful for describing events and coverage, meaning tables contain information that nothing has happened. It often represents many-to-many relationships. The only thing they have is an abbreviated key.
Why do we use facts and dimensions?
Why should we separate dimension and facts instead of combining both in one table. need some insight in dimensional modeling or star schema. Having dimensions in fact table will makes query run very fast and no need to maintain dimension table separately, no need to look up dimension table when doing ETL.
When would it be appropriate to use factless fact tables?
What is factless fact table explain with example?
A factless fact table is a fact table that does not have any measures. It is essentially an intersection of dimensions (it contains nothing but dimensional keys). There are two types of factless tables: One is for capturing an event, and one is for describing conditions.
What is the meaning of Factless?
Filters. Lacking facts; inaccurate or fictional.
Is there such a thing as a factless fact table?
By definition, the factless fact table is a fact table that does not contain any facts. There are two kinds of factless fact tables: Factless fact table describes event or activity.
Why do you need fact tables in a design?
Recognizing multiple business processes will result in a simplified design for the core transaction and snapshot fact tables surrounded by several factless fact tables that help track the relationship between other dimension tables. To finish our example, a property and casualty design might include factless fact tables to support:
Why do you need a snapshot fact table?
Likewise, it makes perfect sense to implement a monthly snapshot fact table to capture the earned premium associated with every policy by customer, by named insured, by household, by vehicle, by driver and so on.
Can a fact table capture the relationship of a claim?
Another factless fact table can capture the relationship of each claim handler, their role, the coverage and other details of the claim.