⟩ Explain me what are the different types of fact tables used in data warehousing?
There are three types of fact tables that are used and the characterization is given below:
Transactional Table: It is the most basic table of data warehousing. It consists of grain that has the association with the transactional fact table and it is defines to use one row per line in a transactional. It consists of the most detailed data that have many number of dimensions associated with it.
Periodic snapshots: It is used to take the snapshot of the currently working data set. It depends on the period of time when the snapshots are taken. It increases the performance. This table is dependent on the transactional table as it has to be synchronized to keep all the detailed data that is mentioned in transactional table. The snapshot can be looked if any problem take place in the database and it helps in recovering the state that is lost.
Accumulating snapshots: This type of table is used to show the activity of the process that is defined from the beginning till end. For example, order process. The snapshots consist of multiple date columns that represent a timeline of the process. It keeps and entry of the associate date dimension representing the unknown date.
