The Fact Table in Data Warehouse is the central table of the star schema. It stores the quantitative data in a denormalized format and is used for analysis purposes. It works with various dimensional tables and consists of the data that needs to be analyzed. The dimensional table, on the other hand, stores information about the methods in which you can analyze the data.
The fact table contains two distinct types of columns – the foreign keys column and the measure columns. The foreign keys column helps to join with the dimension tables while the measure columns consist of the data that has to be analyzed.
A fact table can be categorized into the following three types:
- Transactional Fact Table: It helps in storing detailed-level data due to which it has various dimensions associated with it.
- Periodic Snapshots Fact Table: It stores data that is a snapshot in a particular time period. The source data of this table is the transaction fact table from which you can choose the time period and get the required output.
- Accumulating Snapshots Fact Table: It describes the complete business process because of which it consists of multiple date columns that can represent milestones in the process.
To learn more about fact tables, you must enroll in an online Data Warehousing Training.
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