What is degenerate dimension?

< 1 min read

A degenerate dimension is a dimension attribute stored directly in the fact table without a separate dimension table.
It usually has no descriptive attributes associated with it.
Common examples are order_id, invoice_number, ticket_number.
In one sales project, order_id was stored in the fact table as a degenerate dimension.
We did not create a separate Order dimension because it had no additional details.
It was mainly used for drill-down and transaction-level tracking.
This keeps the model simple and avoids unnecessary joins.
It is typically used for high-cardinality transactional identifiers.

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