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Define dimension table

Short answer

A dimension table stores descriptive attributes (e.g., product, time) with a primary key linked to a fact table. It enables filtering and grouping. Example: Item(item_key, item_name, brand, type, supplier) and Time(time_key, day, month, quarter, year).

Define Dimension table with example.

A dimension table is a table in a dimensional schema that holds the descriptive attributes about a business entity by which facts are viewed, such as time, product, location or customer. It has a primary key referenced by the fact table and many text attributes, often forming a hierarchy (day, month, quarter, year). It is smaller than the fact table and is used for filtering, grouping and labelling the results.

Example: Item(item_key, item_name, brand, type, supplier) and Time(time_key, day, month, quarter, year). A query such as "total sales by brand in 2025" uses the dimensions Item and Time to group and filter the facts.

✓ Answer checked by Claude Opus 5.5 (high effort)

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