What is a dimension table used for?

• A. Store descriptive attributes used to constrain or categorize facts.
• B. Store detailed transactional logs.
• C. Store aggregated measures.
• D. Store only surrogate keys.

Answer: (A)

In dimensional modeling, a dimension table holds the descriptive attributes that describe each member of a business dimension—things like product name, category, color, customer region, or time attributes. These attributes are what you use to constrain, filter, and group the facts in the fact table, enabling meaningful analysis and reporting. That’s why this option is the best: it captures the role of a dimension table as the source of context and categorization for the numeric measures stored in facts. It isn’t about storing detailed transactional logs (that’s what a fact table does), nor about storing aggregated measures (those are derived or summarized data, often still part of fact structures or separate summary tables). A dimension table may use a surrogate key as its primary key, but its purpose is to provide descriptive attributes for labeling and slicing data, not to store only keys.