What is a factless fact table explain with example?
1 Answer. A factless fact table is a fact table that does not have any measures, i.e. any numeric fields that can be aggregated. For example, if you are modelling product sales, you can have a Sales fact table that will contain the dimension keys and, for example, the “amount” value/measure, to record the amount sold.
What is fact table in data warehouse with example?
A fact table is the central table in a star schema of a data warehouse. A fact table stores quantitative information for analysis and is often denormalized. A fact table works with dimension tables.
What is aggregated fact table?
Aggregate fact tables are special fact tables in a data warehouse that contain new metrics derived from one or more aggregate functions (AVERAGE, COUNT, MIN, MAX, etc..) or from other specialized functions that output totals derived from a grouping of the base data.
What is fact table and dimension table in data warehouse with example?
Difference between Dimension table vs. Fact table
| Parameters | Fact Table |
|---|---|
| Definition | Measurements, metrics or facts about a business process. |
| Characteristic | Located at the center of a star or snowflake schema and surrounded by dimensions. |
| Design | Defined by their grain or its most atomic level. |
What are the types of fact tables?
There are three types of fact tables:
- Transaction Fact Table. The transaction fact table is a basic approach to operate the businesses.
- Snapshot Fact Table. The snapshot fact table describes the state of things at a particular time and contains many semi-additive and non-additive facts.
- Accumulated Fact Sheet.
What is aggregated fact?
Aggregates are precalculated summaries derived from the most granular fact table. These summaries form a set of separate aggregate fact tables. These queries retrieve hundreds and thousands of table rows, manipulate the metrics in the fact tables, and then produce the result sets. …
When to use fact less in data warehouse?
The fact-less fact is often used to resolve a many-to-many cardinality issue. Types of Fact-less fact tables in Data Warehouse? This type of fact table establishes the relationship among the various dimension members from various dimension tables without any measured value.
Why are fact tables called factless fact tables?
They are called so because, the fact table does not have aggregatable numeric values or information.There are two types of factless fact tables:those that describe events, and those that describe conditions. Both may play important roles in your dimensional models.
Which is an example of a fact less fact?
For examples, Student attendance (student-teacher relation table) capturing table is the fact-less fact. Table will have entry into it whenever student attend class.
What are the dimensions of a fact table?
In this case, the fact table would consist of 3 dimensions: the student dimension, the time dimension, and the class dimension. This factless fact table would look like the following: