Mumbai University > Information Technology > Sem 5 > Advanced Database Management System

Marks: 10M

Year: Dec 2015

• A fact table without any measures is known as factless fact table. It’s basically an intersection of dimension
• The concept of factless fact table does not make sense & seems to be of not much use because of fact table. Essentially is all about facts, & there are no facts in a factless fact table
• However there are circumstances where using a factless fact table makes sense in data ware housing.
• Factless fact table provide flexibility in data warehouse design
• It contains many-many relationships between dimensions.
• These table do not contain numeric textual facts
• Commonly used in tables such as keeping the attendance record students

e.g.:-

Identifying product promotion events

Tracking attendance of students or registration events.

Tracking insurance related accident events.

There are two types:-

1. Factless fact table for events.
2. Factless fact table for conditions.

• Factless fact table for events:-

  • Factless fact table for events is a table that records events. In dimensional data warehouse, numerous event-tracking tables appear to be factless sometimes, there may be a situation where no fact seems to be related to an important business process & you may have events that you want to track, but you cannot find any measurements. In such situations, create a typical transact-grained fact table that comprises no facts.

• Factless fact table for conditions:-

  • If there are no clear transactions, factless fact tables are used to design the conditions or other important relationships among the different dimensions.

A factless fact table helps in creating analysis reports that comprises negative aspects of a business. For e.g. Book store that did not sell a single book for a given period.