What is a factless fact table used for?

• A. Stores only dimension attributes.
• B. Records events with no measurable facts.
• C. Records the occurrence of events without measurable facts.
• D. Contains only grain information.

Answer: (C)

A factless fact table is used to capture that an event occurred or a relationship between dimensions, without recording any numeric measurement. Each row represents a specific occurrence at a defined level of detail (the grain), defined by the combination of foreign keys to the related dimensions. Since there are no measurable facts like quantities or amounts, analysis is done by counting rows or examining which dimension combinations appear together. For example, you might track that a student attended a class on a given date, or a customer made a visit, with only the dimension keys present and no numeric value attached. The idea is to record the occurrence itself rather than a measurable value.